create table t1 (a int, b varchar(32));
insert into t1 values
(4,'aaaa' ), (7,'bb'), (1,'ccc'), (4,'dd');
insert into t1 values
(3,'eee'), (7,'bb'), (1,'fff'), (4,'ggg');
with recursive
t as 
(
select * from t1 where t1.b >= 'c'
  union
select * from r
),
r as
(
select * from t
union
select t1.* from t1,r where r.a+1 = t1.a
)
select * from r;
ERROR HY000: Unacceptable mutual recursion with anchored table 't'
with recursive
a1(a,b) as
(select * from t1 where t1.a>3
union
select * from b1 where b1.a >3
union
select * from c1 where c1.a>3),
b1(a,b) as
(select * from a1 where a1.b > 'ccc'
union
select * from c1 where c1.b > 'ddd'),
c1(a,b) as
(select * from a1 where a1.a<6 and a1.b< 'zz'
union
select * from b1 where b1.b > 'auu')
select * from c1;
ERROR HY000: Unacceptable mutual recursion with anchored table 'a1'
drop table t1;
# WITH RECURSIVE vs just WITH
create table t1 (a int);
insert into t1 values
(0), (1), (2), (3), (4);
create table t2 (a int);
insert into t2 values
(1), (2), (3), (4), (5);
# just WITH : s refers to t defined after s
with 
s(a) as (select t.a + 10 from t),
t(a) as (select t1.a from t1)
select * from s;
ERROR 42S02: Table 'test.t' doesn't exist
# WITH RECURSIVE: s refers to t defined after s
with recursive 
s(a) as (select t.a + 10 from t),
t(a) as (select t1.a from t1)
select * from s;
a
10
11
12
13
14
# just WITH : defined t1 is non-recursive and uses base tables t1,t2
with
t1 as
(
select a  from t2 where t2.a=3
union
select t2.a from t1,t2 where t1.a+1=t2.a
)
select * from t1;
a
3
1
2
4
5
explain
with
t1 as
(
select a  from t2 where t2.a=3
union
select t2.a from t1,t2 where t1.a+1=t2.a
)
select * from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	30	
2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	Using where
3	UNION	t1	ALL	NULL	NULL	NULL	NULL	5	
3	UNION	t2	ALL	NULL	NULL	NULL	NULL	5	Using where; Using join buffer (flat, BNL join)
NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	
#WITH RECURSIVE : defined t1 is recursive and uses only base table t2
with recursive
t1 as
(
select a  from t2 where t2.a=3
union
select t2.a from t1,t2 where t1.a+1=t2.a
)
select * from t1;
a
3
4
5
explain
with recursive
t1 as
(
select a  from t2 where t2.a=3
union
select t2.a from t1,t2 where t1.a+1=t2.a
)
select * from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	5	
2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	Using where
3	RECURSIVE UNION	<derived2>	ALL	NULL	NULL	NULL	NULL	5	
3	RECURSIVE UNION	t2	ALL	NULL	NULL	NULL	NULL	5	Using where; Using join buffer (flat, BNL join)
NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	
# just WITH : types of t1 columns are determined by all parts of union 
create view v1 as
with
t1 as
(
select a  from t2 where t2.a=3
union
select t2.a+1 from t1,t2 where t1.a=t2.a
)
select * from t1;
show columns from v1;
Field	Type	Null	Key	Default	Extra
a	bigint(20)	YES		NULL	
# WITH RECURSIVE : types of t1 columns are determined by anchor parts 
create view v2 as
with recursive
t1 as
(
select a  from t2 where t2.a=3
union
select t2.a+1 from t1,t2 where t1.a=t2.a
)
select * from t1;
show columns from v2;
Field	Type	Null	Key	Default	Extra
a	int(11)	YES		NULL	
drop view v1,v2;
drop table t1,t2;
create table  folks(id int, name char(32), dob date, father int, mother int);
insert into folks values
(100, 'Me', '2000-01-01', 20, 30),
(20, 'Dad', '1970-02-02', 10, 9),
(30, 'Mom', '1975-03-03', 8, 7),
(10, 'Grandpa Bill', '1940-04-05', null, null),
(9, 'Grandma Ann', '1941-10-15', null, null),
(25, 'Uncle Jim', '1968-11-18', 8, 7),
(98, 'Sister Amy', '2001-06-20', 20, 30),
(7, 'Grandma Sally', '1943-08-23', null, 6),
(8, 'Grandpa Ben', '1940-10-21', null, null),
(6, 'Grandgrandma Martha', '1923-05-17', null, null),
(67, 'Cousin Eddie', '1992-02-28', 25, 27),
(27, 'Auntie Melinda', '1971-03-29', null, null);
# simple recursion with one anchor and one recursive select
# the anchor is the first select in the specification 
with recursive 
ancestors
as
(
select *
from folks
where name = 'Me' and dob = '2000-01-01'
  union 
select p.id, p.name, p.dob, p.father, p.mother
from folks as p, ancestors AS a
where p.id = a.father or p.id = a.mother
)
select * from ancestors;
id	name	dob	father	mother
100	Me	2000-01-01	20	30
20	Dad	1970-02-02	10	9
30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL
9	Grandma Ann	1941-10-15	NULL	NULL
7	Grandma Sally	1943-08-23	NULL	6
8	Grandpa Ben	1940-10-21	NULL	NULL
6	Grandgrandma Martha	1923-05-17	NULL	NULL
# simple recursion with one anchor and one recursive select
# the anchor is the last select in the specification 
with recursive 
ancestors
as
(
select p.*
from folks as p, ancestors AS a
where p.id = a.father or p.id = a.mother
union
select *
from folks
where name = 'Me' and dob = '2000-01-01'
)
select * from ancestors;
id	name	dob	father	mother
100	Me	2000-01-01	20	30
20	Dad	1970-02-02	10	9
30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL
9	Grandma Ann	1941-10-15	NULL	NULL
7	Grandma Sally	1943-08-23	NULL	6
8	Grandpa Ben	1940-10-21	NULL	NULL
6	Grandgrandma Martha	1923-05-17	NULL	NULL
# simple recursion with one anchor and one recursive select
# the anchor is the first select in the specification 
with recursive
ancestors
as
(
select *
from folks
where name = 'Cousin Eddie'
  union 
select p.*
from folks as p, ancestors as a
where p.id = a.father or p.id = a.mother
)
select * from ancestors;
id	name	dob	father	mother
67	Cousin Eddie	1992-02-28	25	27
25	Uncle Jim	1968-11-18	8	7
27	Auntie Melinda	1971-03-29	NULL	NULL
7	Grandma Sally	1943-08-23	NULL	6
8	Grandpa Ben	1940-10-21	NULL	NULL
6	Grandgrandma Martha	1923-05-17	NULL	NULL
# simple recursion with or in anchor and or in recursive part 
with recursive
ancestors
as
(
select *
from  folks
where name = 'Me' or name='Sister Amy'
   union 
select  p.*
from folks as p, ancestors as a
where p.id = a.father or p.id = a.mother
)
select * from ancestors;
id	name	dob	father	mother
100	Me	2000-01-01	20	30
98	Sister Amy	2001-06-20	20	30
20	Dad	1970-02-02	10	9
30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL
9	Grandma Ann	1941-10-15	NULL	NULL
7	Grandma Sally	1943-08-23	NULL	6
8	Grandpa Ben	1940-10-21	NULL	NULL
6	Grandgrandma Martha	1923-05-17	NULL	NULL
# two recursive definition, one uses another
with recursive 
prev_gen
as
(
select folks.*
from folks, prev_gen
where folks.id=prev_gen.father or folks.id=prev_gen.mother
union
select * 
from folks
where name='Me'
),
ancestors
as
(
select *
from folks
where name='Me'
  union 
select *
from ancestors
union
select *
from prev_gen
)
select ancestors.name, ancestors.dob from ancestors;
name	dob
Me	2000-01-01
Dad	1970-02-02
Mom	1975-03-03
Grandpa Bill	1940-04-05
Grandma Ann	1941-10-15
Grandma Sally	1943-08-23
Grandpa Ben	1940-10-21
Grandgrandma Martha	1923-05-17
# recursive definition with two attached non-recursive
with recursive 
ancestors(id,name,dob)
as
(
with 
father(child_id,id,name,dob)
as
(
select folks.id, f.id, f.name, f.dob
from folks, folks f
where folks.father=f.id 
),
mother(child_id,id,name,dob)
as
(
select folks.id, m.id, m.name, m.dob
from folks, folks m
where folks.mother=m.id 
)  
select folks.id, folks.name, folks.dob
from folks
where name='Me'
  union 
select f.id, f.name, f.dob
from ancestors a, father f
where f.child_id=a.id
union 
select m.id, m.name, m.dob
from ancestors a, mother m
where m.child_id=a.id
)
select ancestors.name, ancestors.dob from ancestors;
name	dob
Me	2000-01-01
Dad	1970-02-02
Mom	1975-03-03
Grandpa Bill	1940-04-05
Grandpa Ben	1940-10-21
Grandma Ann	1941-10-15
Grandma Sally	1943-08-23
Grandgrandma Martha	1923-05-17
# simple recursion with one anchor and one recursive select
# the anchor is the first select in the specification 
with recursive
descendants
as
(
select *
from folks
where name = 'Grandpa Bill'
  union 
select folks.*
from folks, descendants as d
where d.id=folks.father or d.id=folks.mother
)
select * from descendants;
id	name	dob	father	mother
10	Grandpa Bill	1940-04-05	NULL	NULL
20	Dad	1970-02-02	10	9
100	Me	2000-01-01	20	30
98	Sister Amy	2001-06-20	20	30
# simple recursion with one anchor and one recursive select
# the anchor is the first select in the specification 
with recursive
descendants
as
(
select *
from folks
where name = 'Grandma Sally'
  union 
select folks.*
from folks, descendants as d
where d.id=folks.father or d.id=folks.mother
)
select * from descendants;
id	name	dob	father	mother
7	Grandma Sally	1943-08-23	NULL	6
30	Mom	1975-03-03	8	7
25	Uncle Jim	1968-11-18	8	7
100	Me	2000-01-01	20	30
98	Sister Amy	2001-06-20	20	30
67	Cousin Eddie	1992-02-28	25	27
# simple recursive table used three times in the main query
with recursive
ancestors
as
(
select *
from folks 
where name = 'Me' and dob = '2000-01-01'
  union
select p.*   
from folks as p, ancestors AS a   
where p.id = a.father OR p.id = a.mother
)
select *
from ancestors t1, ancestors t2 
where exists (select * from ancestors a 
where a.father=t1.id AND a.mother=t2.id);
id	name	dob	father	mother	id	name	dob	father	mother
20	Dad	1970-02-02	10	9	30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL	9	Grandma Ann	1941-10-15	NULL	NULL
8	Grandpa Ben	1940-10-21	NULL	NULL	7	Grandma Sally	1943-08-23	NULL	6
# simple recursive table used three times in the main query
with 
ancestor_couples(husband, h_dob, wife, w_dob)
as
(
with recursive 
ancestors
as
(
select *
from folks 
where name = 'Me'
  union
select p.*   
from folks as p, ancestors AS a   
where p.id = a.father OR p.id = a.mother
)
select t1.name, t1.dob, t2.name, t2.dob
from ancestors t1, ancestors t2 
where exists (select * from ancestors a 
where a.father=t1.id AND a.mother=t2.id)
)
select * from ancestor_couples;
husband	h_dob	wife	w_dob
Dad	1970-02-02	Mom	1975-03-03
Grandpa Bill	1940-04-05	Grandma Ann	1941-10-15
Grandpa Ben	1940-10-21	Grandma Sally	1943-08-23
# simple recursion with two selects in recursive part
with recursive
ancestors
as
(
select *
from folks 
where name = 'Me'
  union 
select p.*
from folks as p, ancestors as fa
where p.id = fa.father
union
select p.*
from folks as p, ancestors as ma
where p.id = ma.mother
)
select * from ancestors;
id	name	dob	father	mother
100	Me	2000-01-01	20	30
20	Dad	1970-02-02	10	9
30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL
8	Grandpa Ben	1940-10-21	NULL	NULL
9	Grandma Ann	1941-10-15	NULL	NULL
7	Grandma Sally	1943-08-23	NULL	6
6	Grandgrandma Martha	1923-05-17	NULL	NULL
# mutual recursion with renaming
with recursive
ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
w_id, w_name, w_dob, w_father, w_mother)
as
(
select h.*, w.*
from folks h, folks w,  coupled_ancestors a
where a.father = h.id AND a.mother = w.id
union
select h.*, w.*
from folks v, folks h, folks w
where v.name = 'Me' and
(v.father = h.id AND v.mother= w.id)
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select h_id, h_name, h_dob, h_father, h_mother
from ancestor_couples
union
select w_id, w_name, w_dob, w_father, w_mother
from ancestor_couples
)
select h_name, h_dob, w_name, w_dob
from ancestor_couples;
h_name	h_dob	w_name	w_dob
Dad	1970-02-02	Mom	1975-03-03
Grandpa Bill	1940-04-05	Grandma Ann	1941-10-15
Grandpa Ben	1940-10-21	Grandma Sally	1943-08-23
# mutual recursion with union all
with recursive
ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
w_id, w_name, w_dob, w_father, w_mother)
as
(
select h.*, w.*
from folks h, folks w,  coupled_ancestors a
where a.father = h.id AND a.mother = w.id
union 
select h.*, w.*
from folks v, folks h, folks w
where v.name = 'Me' and
(v.father = h.id AND v.mother= w.id)
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select h_id, h_name, h_dob, h_father, h_mother
from ancestor_couples
union all
select w_id, w_name, w_dob, w_father, w_mother
from ancestor_couples
)
select h_name, h_dob, w_name, w_dob
from ancestor_couples;
h_name	h_dob	w_name	w_dob
Dad	1970-02-02	Mom	1975-03-03
Grandpa Bill	1940-04-05	Grandma Ann	1941-10-15
Grandpa Ben	1940-10-21	Grandma Sally	1943-08-23
# mutual recursion with renaming
with recursive
ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
w_id, w_name, w_dob, w_father, w_mother)
as
(
select h.*, w.*
from folks h, folks w,  coupled_ancestors a
where a.father = h.id AND a.mother = w.id
union
select h.*, w.*
from folks v, folks h, folks w
where v.name = 'Me' and
(v.father = h.id AND v.mother= w.id)
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select h_id, h_name, h_dob, h_father, h_mother
from ancestor_couples
union
select w_id, w_name, w_dob, w_father, w_mother
from ancestor_couples
)
select h_name, h_dob, w_name, w_dob
from ancestor_couples;
h_name	h_dob	w_name	w_dob
Dad	1970-02-02	Mom	1975-03-03
Grandpa Bill	1940-04-05	Grandma Ann	1941-10-15
Grandpa Ben	1940-10-21	Grandma Sally	1943-08-23
# mutual recursion with union all
with recursive
ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
w_id, w_name, w_dob, w_father, w_mother)
as
(
select h.*, w.*
from folks h, folks w,  coupled_ancestors a
where a.father = h.id AND a.mother = w.id
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select * 
from folks 
where name = 'Me'
  union all
select h_id, h_name, h_dob, h_father, h_mother
from ancestor_couples
union all
select w_id, w_name, w_dob, w_father, w_mother
from ancestor_couples
)
select h_name, h_dob, w_name, w_dob
from ancestor_couples;
h_name	h_dob	w_name	w_dob
Dad	1970-02-02	Mom	1975-03-03
Grandpa Bill	1940-04-05	Grandma Ann	1941-10-15
Grandpa Ben	1940-10-21	Grandma Sally	1943-08-23
# mutual recursion with one select in the first definition
with recursive
ancestor_couple_ids(h_id, w_id)
as
(
select a.father, a.mother
from coupled_ancestors a
where a.father is not null and a.mother is not null
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select * 
from folks 
where name = 'Me'
  union all
select p.*
from folks p, ancestor_couple_ids fa
where p.id = fa.h_id
union all
select p.*
from folks p, ancestor_couple_ids ma
where p.id = ma.w_id
)
select *
from ancestor_couple_ids;
h_id	w_id
20	30
10	9
8	7
# join of a mutually recursive table with base tables
with recursive
ancestor_couple_ids(h_id, w_id)
as
(
select a.father, a.mother
from coupled_ancestors a
where a.father is not null and a.mother is not null
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select * 
from folks 
where name = 'Me'
  union all
select p.*
from folks p, ancestor_couple_ids fa
where p.id = fa.h_id
union all
select p.*
from folks p, ancestor_couple_ids ma
where p.id = ma.w_id
)
select h.name, h.dob, w.name, w.dob
from ancestor_couple_ids c, folks h, folks w
where c.h_id = h.id and c.w_id= w.id;
name	dob	name	dob
Dad	1970-02-02	Mom	1975-03-03
Grandpa Bill	1940-04-05	Grandma Ann	1941-10-15
Grandpa Ben	1940-10-21	Grandma Sally	1943-08-23
# join of two mutually recursive tables
with recursive
ancestor_couple_ids(h_id, w_id)
as
(
select a.father, a.mother
from coupled_ancestors a
where a.father is not null and a.mother is not null
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select * 
from folks 
where name = 'Me'
  union all
select p.*
from folks p, ancestor_couple_ids fa
where p.id = fa.h_id
union all
select p.*
from folks p, ancestor_couple_ids ma
where p.id = ma.w_id
)
select h.name, h.dob, w.name, w.dob
from ancestor_couple_ids c, coupled_ancestors h, coupled_ancestors w
where c.h_id = h.id and c.w_id= w.id;
name	dob	name	dob
Dad	1970-02-02	Mom	1975-03-03
Grandpa Bill	1940-04-05	Grandma Ann	1941-10-15
Grandpa Ben	1940-10-21	Grandma Sally	1943-08-23
explain extended
with recursive
ancestor_couple_ids(h_id, w_id)
as
(
select a.father, a.mother
from coupled_ancestors a
where a.father is not null and a.mother is not null
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select * 
from folks 
where name = 'Me'
  union all
select p.*
from folks p, ancestor_couple_ids fa
where p.id = fa.h_id
union all
select p.*
from folks p, ancestor_couple_ids ma
where p.id = ma.w_id
)
select h.name, h.dob, w.name, w.dob
from ancestor_couple_ids c, coupled_ancestors h, coupled_ancestors w
where c.h_id = h.id and c.w_id= w.id;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
1	PRIMARY	<derived3>	ref	key0	key0	5	c.h_id	2	100.00	
1	PRIMARY	<derived3>	ref	key0	key0	5	c.w_id	2	100.00	
3	SUBQUERY	folks	ALL	NULL	NULL	NULL	NULL	12	100.00	Using where
4	RECURSIVE UNION	<derived2>	ALL	NULL	NULL	NULL	NULL	2	100.00	
4	RECURSIVE UNION	p	ALL	NULL	NULL	NULL	NULL	12	100.00	Using where; Using join buffer (flat, BNL join)
5	RECURSIVE UNION	<derived2>	ALL	NULL	NULL	NULL	NULL	2	100.00	
5	RECURSIVE UNION	p	ALL	NULL	NULL	NULL	NULL	12	100.00	Using where; Using join buffer (flat, BNL join)
NULL	UNION RESULT	<union3,4,5>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
2	UNCACHEABLE SUBQUERY	<derived3>	ALL	NULL	NULL	NULL	NULL	12	100.00	Using where
Warnings:
Note	1003	with recursive ancestor_couple_ids as (select `a`.`father` AS `h_id`,`a`.`mother` AS `w_id` from `coupled_ancestors` `a` where `a`.`father` is not null and `a`.`mother` is not null), coupled_ancestors as (select `test`.`folks`.`id` AS `id`,`test`.`folks`.`name` AS `name`,`test`.`folks`.`dob` AS `dob`,`test`.`folks`.`father` AS `father`,`test`.`folks`.`mother` AS `mother` from `test`.`folks` where `test`.`folks`.`name` = 'Me' union all select `test`.`p`.`id` AS `id`,`test`.`p`.`name` AS `name`,`test`.`p`.`dob` AS `dob`,`test`.`p`.`father` AS `father`,`test`.`p`.`mother` AS `mother` from `test`.`folks` `p` join `ancestor_couple_ids` `fa` where `test`.`p`.`id` = `fa`.`h_id` union all select `test`.`p`.`id` AS `id`,`test`.`p`.`name` AS `name`,`test`.`p`.`dob` AS `dob`,`test`.`p`.`father` AS `father`,`test`.`p`.`mother` AS `mother` from `test`.`folks` `p` join `ancestor_couple_ids` `ma` where `test`.`p`.`id` = `ma`.`w_id`)select `h`.`name` AS `name`,`h`.`dob` AS `dob`,`w`.`name` AS `name`,`w`.`dob` AS `dob` from `ancestor_couple_ids` `c` join `coupled_ancestors` `h` join `coupled_ancestors` `w` where `h`.`id` = `c`.`h_id` and `w`.`id` = `c`.`w_id`
# simple mutual recursion
with recursive
ancestor_couple_ids(h_id, w_id)
as
(
select a.father, a.mother
from coupled_ancestors a
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select * 
from folks 
where name = 'Me'
  union all
select p.*
from folks p, ancestor_couple_ids fa
where p.id = fa.h_id
union all
select p.*
from folks p, ancestor_couple_ids ma
where p.id = ma.w_id
)
select *
from ancestor_couple_ids;
h_id	w_id
20	30
10	9
8	7
NULL	NULL
NULL	NULL
NULL	NULL
NULL	6
NULL	NULL
# join of two mutually recursive tables
with recursive
ancestor_couple_ids(h_id, w_id)
as
(
select a.father, a.mother
from coupled_ancestors a
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select * 
from folks 
where name = 'Me'
  union all
select p.*
from folks p, ancestor_couple_ids fa
where p.id = fa.h_id
union all
select p.*
from folks p, ancestor_couple_ids ma
where p.id = ma.w_id
)
select h.name, h.dob, w.name, w.dob
from ancestor_couple_ids c, coupled_ancestors h, coupled_ancestors w
where c.h_id = h.id and c.w_id= w.id;
name	dob	name	dob
Dad	1970-02-02	Mom	1975-03-03
Grandpa Bill	1940-04-05	Grandma Ann	1941-10-15
Grandpa Ben	1940-10-21	Grandma Sally	1943-08-23
# execution of prepared query using a recursive table
prepare stmt1 from "
with recursive 
ancestors
as
(
  select *
    from folks
      where name = 'Me' and dob = '2000-01-01'
  union 
  select p.id, p.name, p.dob, p.father, p.mother
    from folks as p, ancestors AS a
      where p.id = a.father or p.id = a.mother
)
select * from ancestors;
";
execute stmt1;
id	name	dob	father	mother
100	Me	2000-01-01	20	30
20	Dad	1970-02-02	10	9
30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL
9	Grandma Ann	1941-10-15	NULL	NULL
7	Grandma Sally	1943-08-23	NULL	6
8	Grandpa Ben	1940-10-21	NULL	NULL
6	Grandgrandma Martha	1923-05-17	NULL	NULL
execute stmt1;
id	name	dob	father	mother
100	Me	2000-01-01	20	30
20	Dad	1970-02-02	10	9
30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL
9	Grandma Ann	1941-10-15	NULL	NULL
7	Grandma Sally	1943-08-23	NULL	6
8	Grandpa Ben	1940-10-21	NULL	NULL
6	Grandgrandma Martha	1923-05-17	NULL	NULL
deallocate prepare stmt1;
# view using a recursive table
create view v1 as
with recursive 
ancestors
as
(
select *
from folks
where name = 'Me' and dob = '2000-01-01'
  union 
select p.id, p.name, p.dob, p.father, p.mother
from folks as p, ancestors AS a
where p.id = a.father or p.id = a.mother
)
select * from ancestors;
show create view v1;
View	Create View	character_set_client	collation_connection
v1	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v1` AS with recursive ancestors as (select `folks`.`id` AS `id`,`folks`.`name` AS `name`,`folks`.`dob` AS `dob`,`folks`.`father` AS `father`,`folks`.`mother` AS `mother` from `folks` where `folks`.`name` = 'Me' and `folks`.`dob` = '2000-01-01' union select `p`.`id` AS `id`,`p`.`name` AS `name`,`p`.`dob` AS `dob`,`p`.`father` AS `father`,`p`.`mother` AS `mother` from (`folks` `p` join `ancestors` `a`) where `p`.`id` = `a`.`father` or `p`.`id` = `a`.`mother`)select `ancestors`.`id` AS `id`,`ancestors`.`name` AS `name`,`ancestors`.`dob` AS `dob`,`ancestors`.`father` AS `father`,`ancestors`.`mother` AS `mother` from `ancestors`	latin1	latin1_swedish_ci
select * from v1;
id	name	dob	father	mother
100	Me	2000-01-01	20	30
20	Dad	1970-02-02	10	9
30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL
9	Grandma Ann	1941-10-15	NULL	NULL
7	Grandma Sally	1943-08-23	NULL	6
8	Grandpa Ben	1940-10-21	NULL	NULL
6	Grandgrandma Martha	1923-05-17	NULL	NULL
create view v2 as
with recursive
ancestors
as
(
select *
from folks 
where name = 'Me'
  union 
select p.*
from folks as p, ancestors as fa
where p.id = fa.father
union
select p.*
from folks as p, ancestors as ma
where p.id = ma.mother
)
select * from ancestors;
show create view v2;
View	Create View	character_set_client	collation_connection
v2	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v2` AS with recursive ancestors as (select `folks`.`id` AS `id`,`folks`.`name` AS `name`,`folks`.`dob` AS `dob`,`folks`.`father` AS `father`,`folks`.`mother` AS `mother` from `folks` where `folks`.`name` = 'Me' union select `p`.`id` AS `id`,`p`.`name` AS `name`,`p`.`dob` AS `dob`,`p`.`father` AS `father`,`p`.`mother` AS `mother` from (`folks` `p` join `ancestors` `fa`) where `p`.`id` = `fa`.`father` union select `p`.`id` AS `id`,`p`.`name` AS `name`,`p`.`dob` AS `dob`,`p`.`father` AS `father`,`p`.`mother` AS `mother` from (`folks` `p` join `ancestors` `ma`) where `p`.`id` = `ma`.`mother`)select `ancestors`.`id` AS `id`,`ancestors`.`name` AS `name`,`ancestors`.`dob` AS `dob`,`ancestors`.`father` AS `father`,`ancestors`.`mother` AS `mother` from `ancestors`	latin1	latin1_swedish_ci
select * from v2;
id	name	dob	father	mother
100	Me	2000-01-01	20	30
20	Dad	1970-02-02	10	9
30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL
8	Grandpa Ben	1940-10-21	NULL	NULL
9	Grandma Ann	1941-10-15	NULL	NULL
7	Grandma Sally	1943-08-23	NULL	6
6	Grandgrandma Martha	1923-05-17	NULL	NULL
drop view v1,v2;
explain extended
with recursive 
ancestors
as
(
select *
from folks
where name = 'Me' and dob = '2000-01-01'
  union 
select p.id, p.name, p.dob, p.father, p.mother
from folks as p, ancestors AS a
where p.id = a.father or p.id = a.mother
)
select * from ancestors;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	12	100.00	
2	SUBQUERY	folks	ALL	NULL	NULL	NULL	NULL	12	100.00	Using where
3	RECURSIVE UNION	p	ALL	NULL	NULL	NULL	NULL	12	100.00	
3	RECURSIVE UNION	<derived2>	ALL	NULL	NULL	NULL	NULL	12	100.00	Using where; Using join buffer (flat, BNL join)
NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
Warnings:
Note	1003	with recursive ancestors as (select `test`.`folks`.`id` AS `id`,`test`.`folks`.`name` AS `name`,`test`.`folks`.`dob` AS `dob`,`test`.`folks`.`father` AS `father`,`test`.`folks`.`mother` AS `mother` from `test`.`folks` where `test`.`folks`.`name` = 'Me' and `test`.`folks`.`dob` = DATE'2000-01-01' union select `p`.`id` AS `id`,`p`.`name` AS `name`,`p`.`dob` AS `dob`,`p`.`father` AS `father`,`p`.`mother` AS `mother` from `test`.`folks` `p` join `ancestors` `a` where `a`.`father` = `p`.`id` or `a`.`mother` = `p`.`id`)select `ancestors`.`id` AS `id`,`ancestors`.`name` AS `name`,`ancestors`.`dob` AS `dob`,`ancestors`.`father` AS `father`,`ancestors`.`mother` AS `mother` from `ancestors`
# recursive spec with two anchor selects and two recursive ones 
with recursive
ancestor_ids (id)
as
(
select father from folks where name = 'Me'
  union
select mother from folks where name = 'Me'
  union
select father from folks, ancestor_ids a  where folks.id = a.id
union
select mother from folks, ancestor_ids a  where folks.id = a.id
),
ancestors 
as
(
select p.* from folks as p, ancestor_ids as a
where p.id = a.id
)
select * from ancestors;
id	name	dob	father	mother
20	Dad	1970-02-02	10	9
30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL
9	Grandma Ann	1941-10-15	NULL	NULL
7	Grandma Sally	1943-08-23	NULL	6
8	Grandpa Ben	1940-10-21	NULL	NULL
6	Grandgrandma Martha	1923-05-17	NULL	NULL
# recursive spec using union all 
with recursive
ancestors
as
(
select *
from folks 
where name = 'Me'
  union all
select p.*
from folks as p, ancestors as fa
where p.id = fa.father
union all
select p.*
from folks as p, ancestors as ma
where p.id = ma.mother
)
select * from ancestors;
id	name	dob	father	mother
100	Me	2000-01-01	20	30
20	Dad	1970-02-02	10	9
30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL
8	Grandpa Ben	1940-10-21	NULL	NULL
9	Grandma Ann	1941-10-15	NULL	NULL
7	Grandma Sally	1943-08-23	NULL	6
6	Grandgrandma Martha	1923-05-17	NULL	NULL
with recursive
ancestor_ids (id, generation)
as
(
select father, 1 from folks where name = 'Me' and  father is not null
union all
select mother, 1 from folks where name = 'Me' and  mother is not null
union all
select father, fa.generation+1 from folks, ancestor_ids fa
where folks.id = fa.id and (father not in (select id from ancestor_ids))
union all
select mother, ma.generation+1 from folks, ancestor_ids ma
where folks.id = ma.id and (mother not in (select id from ancestor_ids))
)
select generation, name from ancestor_ids a, folks
where a.id = folks.id;
ERROR HY000: Restrictions imposed on recursive definitions are violated for table 'ancestor_ids'
set standard_compliant_cte=0;
with recursive
ancestor_ids (id, generation)
as
(
select father from folks where name = 'Me' and  father is not null
union all
select mother from folks where name = 'Me' and  mother is not null
union all
select father, fa.generation+1 from folks, ancestor_ids fa
where folks.id = fa.id and (father not in (select id from ancestor_ids))
union all
select mother, ma.generation+1 from folks, ancestor_ids ma
where folks.id = ma.id and (mother not in (select id from ancestor_ids))
)
select generation, name from ancestor_ids a, folks
where a.id = folks.id;
ERROR HY000: WITH column list and SELECT field list have different column counts
with recursive
ancestor_ids (id, generation)
as
(
select father, 1 from folks where name = 'Me' and  father is not null
union all
select mother, 1 from folks where name = 'Me' and  mother is not null
union all
select father, fa.generation+1 from folks, ancestor_ids fa
where folks.id = fa.id and father is not null and
(father not in (select id from ancestor_ids))
union all
select mother, ma.generation+1 from folks, ancestor_ids ma
where folks.id = ma.id and mother is not null and
(mother not in (select id from ancestor_ids))
)
select generation, name from ancestor_ids a, folks
where a.id = folks.id;
generation	name
1	Dad
1	Mom
2	Grandpa Bill
2	Grandma Ann
2	Grandma Sally
2	Grandpa Ben
3	Grandgrandma Martha
set standard_compliant_cte=1;
with recursive
coupled_ancestor_ids (id)
as
(
select father from folks where name = 'Me' and father is not null
union 
select mother from folks where name = 'Me' and mother is not null
union
select n.father 
from folks, coupled_ancestor_ids fa, coupled_ancestor_ids ma, folks n
where folks.father = fa.id and folks.mother = ma.id and
(fa.id = n.id or ma.id = n.id) and
n.father is not null and n.mother is not null 
union
select n.mother 
from folks, coupled_ancestor_ids fa, coupled_ancestor_ids ma, folks n
where folks.father = fa.id and folks.mother = ma.id and 
(fa.id = n.id or ma.id = n.id) and 
n.father is not null and n.mother is not null 
)
select p.* from coupled_ancestor_ids a, folks p
where a.id = p.id;
ERROR HY000: Restrictions imposed on recursive definitions are violated for table 'coupled_ancestor_ids'
set statement standard_compliant_cte=0 for
with recursive
coupled_ancestor_ids (id)
as
(
select father from folks where name = 'Me' and father is not null
union 
select mother from folks where name = 'Me' and mother is not null
union
select n.father 
from folks, coupled_ancestor_ids fa, coupled_ancestor_ids ma, folks n
where folks.father = fa.id and folks.mother = ma.id and
(fa.id = n.id or ma.id = n.id) and
n.father is not null and n.mother is not null 
union
select n.mother 
from folks, coupled_ancestor_ids fa, coupled_ancestor_ids ma, folks n
where folks.father = fa.id and folks.mother = ma.id and 
(fa.id = n.id or ma.id = n.id) and 
n.father is not null and n.mother is not null 
)
select p.* from coupled_ancestor_ids a, folks p
where a.id = p.id;
id	name	dob	father	mother
20	Dad	1970-02-02	10	9
30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL
9	Grandma Ann	1941-10-15	NULL	NULL
7	Grandma Sally	1943-08-23	NULL	6
8	Grandpa Ben	1940-10-21	NULL	NULL
with recursive
ancestor_ids (id)
as
(
select father from folks where name = 'Me'
  union
select mother from folks where name = 'Me'
  union
select father from folks left join ancestor_ids a on folks.id = a.id
union
select mother from folks left join ancestor_ids a on folks.id = a.id
),
ancestors 
as
(
select p.* from folks as p, ancestor_ids as a
where p.id = a.id
)
select * from ancestors;
ERROR HY000: Restrictions imposed on recursive definitions are violated for table 'ancestor_ids'
set statement standard_compliant_cte=0 for
with recursive
ancestor_ids (id)
as
(
select father from folks where name = 'Me'
  union
select mother from folks where name = 'Me'
  union
select father from folks left join ancestor_ids a on folks.id = a.id
union
select mother from folks left join ancestor_ids a on folks.id = a.id
),
ancestors 
as
(
select p.* from folks as p, ancestor_ids as a
where p.id = a.id
)
select * from ancestors;
id	name	dob	father	mother
20	Dad	1970-02-02	10	9
30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL
9	Grandma Ann	1941-10-15	NULL	NULL
25	Uncle Jim	1968-11-18	8	7
7	Grandma Sally	1943-08-23	NULL	6
8	Grandpa Ben	1940-10-21	NULL	NULL
6	Grandgrandma Martha	1923-05-17	NULL	NULL
27	Auntie Melinda	1971-03-29	NULL	NULL
with recursive
ancestor_ids (id, generation)
as
(
select father, 1 from folks where name = 'Me'
  union
select mother, 1 from folks where name = 'Me'
  union
select father, a.generation+1 from folks, ancestor_ids a
where folks.id = a.id
union
select mother, a.generation+1 from folks, ancestor_ids a
where folks.id = a.id
),
ancestors 
as
(
select generation, name from folks as p, ancestor_ids as a
where p.id = a.id
)
select * from ancestors;
generation	name
1	Dad
1	Mom
2	Grandpa Bill
2	Grandma Ann
2	Grandma Sally
2	Grandpa Ben
3	Grandgrandma Martha
with recursive
ancestor_ids (id, generation)
as
(
select father, 1 from folks where name = 'Me'
  union
select mother, 1 from folks where name = 'Me'
  union
select max(father), max(a.generation)+1 from folks, ancestor_ids a
where folks.id = a.id
group by a.generation
union
select max(mother), max(a.generation)+1 from folks, ancestor_ids a
where folks.id = a.id
group by a.generation
),
ancestors 
as
(
select generation, name from folks as p, ancestor_ids as a
where p.id = a.id
)
select * from ancestors;
ERROR HY000: Restrictions imposed on recursive definitions are violated for table 'ancestor_ids'
set statement standard_compliant_cte=0 for
with recursive
ancestor_ids (id, generation)
as
(
select father, 1 from folks where name = 'Me'
  union
select mother, 1 from folks where name = 'Me'
  union
select max(father), a.generation+1 from folks, ancestor_ids a
where folks.id = a.id
group by a.generation
union
select max(mother), a.generation+1 from folks, ancestor_ids a
where folks.id = a.id
group by a.generation
),
ancestors 
as
(
select generation, name from folks as p, ancestor_ids as a
where p.id = a.id
)
select * from ancestors;
generation	name
1	Dad
1	Mom
2	Grandpa Bill
2	Grandma Ann
set statement max_recursive_iterations=1 for
with recursive
ancestor_ids (id, generation)
as
(
select father, 1 from folks where name = 'Me'
  union
select mother, 1 from folks where name = 'Me'
  union
select father, a.generation+1 from folks, ancestor_ids a
where folks.id = a.id
union
select mother, a.generation+1 from folks, ancestor_ids a
where folks.id = a.id
),
ancestors 
as
(
select generation, name from folks as p, ancestor_ids as a
where p.id = a.id
)
select * from ancestors;
generation	name
1	Dad
1	Mom
2	Grandpa Bill
2	Grandma Ann
2	Grandma Sally
2	Grandpa Ben
# query with recursive tables using key access
alter table folks add primary key (id);
explain
with recursive
ancestors
as
(
select *
from folks 
where name = 'Me'
  union 
select p.*
from folks as p, ancestors as fa
where p.id = fa.father
union
select p.*
from folks as p, ancestors as ma
where p.id = ma.mother
)
select * from ancestors;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	12	
2	SUBQUERY	folks	ALL	NULL	NULL	NULL	NULL	12	Using where
3	RECURSIVE UNION	p	ALL	PRIMARY	NULL	NULL	NULL	12	
3	RECURSIVE UNION	<derived2>	ref	key0	key0	5	test.p.id	2	
4	RECURSIVE UNION	p	ALL	PRIMARY	NULL	NULL	NULL	12	
4	RECURSIVE UNION	<derived2>	ref	key0	key0	5	test.p.id	2	
NULL	UNION RESULT	<union2,3,4>	ALL	NULL	NULL	NULL	NULL	NULL	
with recursive
ancestors
as
(
select *
from folks 
where name = 'Me'
  union 
select p.*
from folks as p, ancestors as fa
where p.id = fa.father
union
select p.*
from folks as p, ancestors as ma
where p.id = ma.mother
)
select * from ancestors;
id	name	dob	father	mother
100	Me	2000-01-01	20	30
20	Dad	1970-02-02	10	9
30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL
8	Grandpa Ben	1940-10-21	NULL	NULL
9	Grandma Ann	1941-10-15	NULL	NULL
7	Grandma Sally	1943-08-23	NULL	6
6	Grandgrandma Martha	1923-05-17	NULL	NULL
#
# EXPLAIN FORMAT=JSON on a query where one recursive CTE uses another:
#
explain 
with recursive 
prev_gen
as
(
select folks.*
from folks, prev_gen
where folks.id=prev_gen.father or folks.id=prev_gen.mother
union
select * 
from folks
where name='Me'
),
ancestors
as
(
select *
from folks
where name='Me'
  union 
select *
from ancestors
union
select *
from prev_gen
)
select ancestors.name, ancestors.dob from ancestors;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	<derived4>	ALL	NULL	NULL	NULL	NULL	24	
4	SUBQUERY	folks	ALL	NULL	NULL	NULL	NULL	12	Using where
6	RECURSIVE UNION	<derived3>	ALL	NULL	NULL	NULL	NULL	12	
5	RECURSIVE UNION	<derived4>	ALL	NULL	NULL	NULL	NULL	24	
NULL	UNION RESULT	<union4,6,5>	ALL	NULL	NULL	NULL	NULL	NULL	
3	SUBQUERY	folks	ALL	NULL	NULL	NULL	NULL	12	Using where
2	RECURSIVE UNION	folks	ALL	PRIMARY	NULL	NULL	NULL	12	
2	RECURSIVE UNION	<derived3>	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
NULL	UNION RESULT	<union3,2>	ALL	NULL	NULL	NULL	NULL	NULL	
explain FORMAT=JSON
with recursive 
prev_gen
as
(
select folks.*
from folks, prev_gen
where folks.id=prev_gen.father or folks.id=prev_gen.mother
union
select * 
from folks
where name='Me'
),
ancestors
as
(
select *
from folks
where name='Me2'
  union 
select *
from ancestors where id < 234
union
select *
from prev_gen where id < 345
)
select ancestors.name, ancestors.dob from ancestors;
EXPLAIN
{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "<derived4>",
      "access_type": "ALL",
      "rows": 24,
      "filtered": 100,
      "materialized": {
        "query_block": {
          "recursive_union": {
            "table_name": "<union4,6,5>",
            "access_type": "ALL",
            "query_specifications": [
              {
                "query_block": {
                  "select_id": 4,
                  "table": {
                    "table_name": "folks",
                    "access_type": "ALL",
                    "rows": 12,
                    "filtered": 100,
                    "attached_condition": "folks.`name` = 'Me2'"
                  }
                }
              },
              {
                "query_block": {
                  "select_id": 6,
                  "table": {
                    "table_name": "<derived3>",
                    "access_type": "ALL",
                    "rows": 12,
                    "filtered": 100,
                    "attached_condition": "prev_gen.`id` < 345",
                    "materialized": {
                      "query_block": {
                        "recursive_union": {
                          "table_name": "<union3,2>",
                          "access_type": "ALL",
                          "query_specifications": [
                            {
                              "query_block": {
                                "select_id": 3,
                                "table": {
                                  "table_name": "folks",
                                  "access_type": "ALL",
                                  "rows": 12,
                                  "filtered": 100,
                                  "attached_condition": "folks.`name` = 'Me'"
                                }
                              }
                            },
                            {
                              "query_block": {
                                "select_id": 2,
                                "table": {
                                  "table_name": "folks",
                                  "access_type": "ALL",
                                  "possible_keys": ["PRIMARY"],
                                  "rows": 12,
                                  "filtered": 100
                                },
                                "block-nl-join": {
                                  "table": {
                                    "table_name": "<derived3>",
                                    "access_type": "ALL",
                                    "rows": 12,
                                    "filtered": 100
                                  },
                                  "buffer_type": "flat",
                                  "buffer_size": "256Kb",
                                  "join_type": "BNL",
                                  "attached_condition": "prev_gen.father = folks.`id` or prev_gen.mother = folks.`id`"
                                }
                              }
                            }
                          ]
                        }
                      }
                    }
                  }
                }
              },
              {
                "query_block": {
                  "select_id": 5,
                  "table": {
                    "table_name": "<derived4>",
                    "access_type": "ALL",
                    "rows": 24,
                    "filtered": 100,
                    "attached_condition": "ancestors.`id` < 234"
                  }
                }
              }
            ]
          }
        }
      }
    }
  }
}
#
explain format=json
with recursive
ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
w_id, w_name, w_dob, w_father, w_mother)
as
(
select h.*, w.*
from folks h, folks w,  coupled_ancestors a
where a.father = h.id AND a.mother = w.id
union 
select h.*, w.*
from folks v, folks h, folks w
where v.name = 'Me' and
(v.father = h.id AND v.mother= w.id)
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select h_id, h_name, h_dob, h_father, h_mother
from ancestor_couples
union all
select w_id, w_name, w_dob, w_father, w_mother
from ancestor_couples
)
select h_name, h_dob, w_name, w_dob
from ancestor_couples;
EXPLAIN
{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "<derived3>",
      "access_type": "ALL",
      "rows": 12,
      "filtered": 100,
      "materialized": {
        "query_block": {
          "recursive_union": {
            "table_name": "<union3,2>",
            "access_type": "ALL",
            "query_specifications": [
              {
                "query_block": {
                  "select_id": 3,
                  "table": {
                    "table_name": "v",
                    "access_type": "ALL",
                    "rows": 12,
                    "filtered": 100,
                    "attached_condition": "v.`name` = 'Me' and v.father is not null and v.mother is not null"
                  },
                  "table": {
                    "table_name": "h",
                    "access_type": "eq_ref",
                    "possible_keys": ["PRIMARY"],
                    "key": "PRIMARY",
                    "key_length": "4",
                    "used_key_parts": ["id"],
                    "ref": ["test.v.father"],
                    "rows": 1,
                    "filtered": 100
                  },
                  "table": {
                    "table_name": "w",
                    "access_type": "eq_ref",
                    "possible_keys": ["PRIMARY"],
                    "key": "PRIMARY",
                    "key_length": "4",
                    "used_key_parts": ["id"],
                    "ref": ["test.v.mother"],
                    "rows": 1,
                    "filtered": 100
                  }
                }
              },
              {
                "query_block": {
                  "select_id": 2,
                  "table": {
                    "table_name": "<derived4>",
                    "access_type": "ALL",
                    "rows": 2,
                    "filtered": 100,
                    "attached_condition": "a.father is not null and a.mother is not null"
                  },
                  "table": {
                    "table_name": "h",
                    "access_type": "eq_ref",
                    "possible_keys": ["PRIMARY"],
                    "key": "PRIMARY",
                    "key_length": "4",
                    "used_key_parts": ["id"],
                    "ref": ["a.father"],
                    "rows": 1,
                    "filtered": 100
                  },
                  "table": {
                    "table_name": "w",
                    "access_type": "eq_ref",
                    "possible_keys": ["PRIMARY"],
                    "key": "PRIMARY",
                    "key_length": "4",
                    "used_key_parts": ["id"],
                    "ref": ["a.mother"],
                    "rows": 1,
                    "filtered": 100
                  }
                }
              }
            ]
          }
        }
      }
    }
  }
}
create table my_ancestors
with recursive
ancestor_ids (id)
as
(
select father from folks where name = 'Me'
  union
select mother from folks where name = 'Me'
  union
select father from folks, ancestor_ids a  where folks.id = a.id
union
select mother from folks, ancestor_ids a  where folks.id = a.id
)
select p.* from folks as p, ancestor_ids as a where p.id = a.id;
select * from my_ancestors;
id	name	dob	father	mother
20	Dad	1970-02-02	10	9
30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL
9	Grandma Ann	1941-10-15	NULL	NULL
7	Grandma Sally	1943-08-23	NULL	6
8	Grandpa Ben	1940-10-21	NULL	NULL
6	Grandgrandma Martha	1923-05-17	NULL	NULL
delete from my_ancestors;
insert into my_ancestors 
with recursive
ancestor_ids (id)
as
(
select father from folks where name = 'Me'
  union
select mother from folks where name = 'Me'
  union
select father from folks, ancestor_ids a  where folks.id = a.id
union
select mother from folks, ancestor_ids a  where folks.id = a.id
)
select p.* from folks as p, ancestor_ids as a where p.id = a.id;
select * from my_ancestors;
id	name	dob	father	mother
20	Dad	1970-02-02	10	9
30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL
9	Grandma Ann	1941-10-15	NULL	NULL
7	Grandma Sally	1943-08-23	NULL	6
8	Grandpa Ben	1940-10-21	NULL	NULL
6	Grandgrandma Martha	1923-05-17	NULL	NULL
drop table my_ancestors;
#
# MDEV-10883: execution of prepared statement from SELECT
#             with recursive CTE that renames columns
#
prepare stmt from"
with recursive
ancestor_ids (id)
as
(
  select father from folks where name = 'Me'
  union
  select mother from folks where name = 'Me'
  union
  select father from folks, ancestor_ids a  where folks.id = a.id
  union
  select mother from folks, ancestor_ids a  where folks.id = a.id
)
select p.* from folks as p, ancestor_ids as a where p.id = a.id;
";
execute stmt;
id	name	dob	father	mother
20	Dad	1970-02-02	10	9
30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL
9	Grandma Ann	1941-10-15	NULL	NULL
7	Grandma Sally	1943-08-23	NULL	6
8	Grandpa Ben	1940-10-21	NULL	NULL
6	Grandgrandma Martha	1923-05-17	NULL	NULL
deallocate prepare stmt;
#
# MDEV-10881: execution of prepared statement from
#             CREATE ... SELECT, INSERT ... SELECT       
#
prepare stmt from"
create table my_ancestors
with recursive
ancestor_ids (id)
as
(
  select father from folks where name = 'Me'
  union
  select mother from folks where name = 'Me'
  union
  select father from folks, ancestor_ids a  where folks.id = a.id
  union
  select mother from folks, ancestor_ids a  where folks.id = a.id
)
select p.* from folks as p, ancestor_ids as a where p.id = a.id;
";
execute stmt;
deallocate prepare stmt;
select * from my_ancestors;
id	name	dob	father	mother
20	Dad	1970-02-02	10	9
30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL
9	Grandma Ann	1941-10-15	NULL	NULL
7	Grandma Sally	1943-08-23	NULL	6
8	Grandpa Ben	1940-10-21	NULL	NULL
6	Grandgrandma Martha	1923-05-17	NULL	NULL
delete from my_ancestors;
prepare stmt from"
insert into my_ancestors
with recursive
ancestor_ids (id)
as
(
  select father from folks where name = 'Me'
  union
  select mother from folks where name = 'Me'
  union
  select father from folks, ancestor_ids a  where folks.id = a.id
  union
  select mother from folks, ancestor_ids a  where folks.id = a.id
)
select p.* from folks as p, ancestor_ids as a where p.id = a.id;
";
execute stmt;
deallocate prepare stmt;
select * from my_ancestors;
id	name	dob	father	mother
20	Dad	1970-02-02	10	9
30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL
9	Grandma Ann	1941-10-15	NULL	NULL
7	Grandma Sally	1943-08-23	NULL	6
8	Grandpa Ben	1940-10-21	NULL	NULL
6	Grandgrandma Martha	1923-05-17	NULL	NULL
drop table my_ancestors;
#
# MDEV-10933: WITH clause together with SELECT in parenthesis
#             CREATE SELECT      
#
create table my_ancestors
(
with recursive
ancestor_ids (id)
as
(
select father from folks where name = 'Me'
  union
select mother from folks where name = 'Me'
  union
select father from folks, ancestor_ids a  where folks.id = a.id
union
select mother from folks, ancestor_ids a  where folks.id = a.id
)
select p.* from folks as p, ancestor_ids as a where p.id = a.id
);
select * from my_ancestors;
id	name	dob	father	mother
20	Dad	1970-02-02	10	9
30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL
9	Grandma Ann	1941-10-15	NULL	NULL
7	Grandma Sally	1943-08-23	NULL	6
8	Grandpa Ben	1940-10-21	NULL	NULL
6	Grandgrandma Martha	1923-05-17	NULL	NULL
drop table my_ancestors;
drop table folks;
#
# MDEV-10372: [bb-10.2-mdev9864 tree] EXPLAIN with recursive CTE enters endless recursion
#
create table t1(a int);
insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
explain format=json 
with recursive t as (select a from t1 union select a+10 from t where a < 1000) 
select  * from t;
EXPLAIN
{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "<derived2>",
      "access_type": "ALL",
      "rows": 10,
      "filtered": 100,
      "materialized": {
        "query_block": {
          "recursive_union": {
            "table_name": "<union2,3>",
            "access_type": "ALL",
            "query_specifications": [
              {
                "query_block": {
                  "select_id": 2,
                  "table": {
                    "table_name": "t1",
                    "access_type": "ALL",
                    "rows": 10,
                    "filtered": 100
                  }
                }
              },
              {
                "query_block": {
                  "select_id": 3,
                  "table": {
                    "table_name": "<derived2>",
                    "access_type": "ALL",
                    "rows": 10,
                    "filtered": 100,
                    "attached_condition": "t.a < 1000"
                  }
                }
              }
            ]
          }
        }
      }
    }
  }
}
drop table t1;
#
# MDEV-10737: recursive union with several anchors at the end
#
WITH RECURSIVE cte(n) AS
( SELECT n+1 FROM cte WHERE n < 5 UNION SELECT 1 UNION SELECT 1 )
SELECT * FROM cte;
n
1
2
3
4
5
#
# MDEV-10736: recursive definition with anchor over a table with blob
#
CREATE TABLE t1 (f VARCHAR(1024));
WITH RECURSIVE cte(f) AS
(SELECT t1.f FROM t1 UNION ALL SELECT cte.f FROM cte) 
SELECT * FROM cte as t;
f
DROP TABLE t1;
#
# MDEV-10899: mergeable derived in the spec of recursive CTE
#
create table t1 (a int);
insert into t1 values
(0), (1), (2), (3), (4);
create table t2 (a int);
insert into t2 values
(1), (2), (3), (4), (5);
with recursive
t1 as
(
select x.a from (select a from t2 where t2.a=3) x
union
select t2.a from t1,t2 where t1.a+1=t2.a
)
select * from t1;
a
3
4
5
explain
with recursive
t1 as
(
select x.a from (select a from t2 where t2.a=3) x
union
select t2.a from t1,t2 where t1.a+1=t2.a
)
select * from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	5	
2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	Using where
4	RECURSIVE UNION	<derived2>	ALL	NULL	NULL	NULL	NULL	5	
4	RECURSIVE UNION	t2	ALL	NULL	NULL	NULL	NULL	5	Using where; Using join buffer (flat, BNL join)
NULL	UNION RESULT	<union2,4>	ALL	NULL	NULL	NULL	NULL	NULL	
drop table t1,t2;
#
# MDEV-11278: non-mergeable view in the spec of recursive CTE
#
create table t1 (a int);
insert into t1 values
(0), (1), (2), (3), (4);
create table t2 (a int);
insert into t2 values
(1), (2), (3), (4), (5);
create view v1 as
select a from t2 where a < 3
union
select a from t2 where a > 4;
with recursive
t1 as
(
select a from v1 where a=1 
union
select v1.a from t1,v1 where t1.a+1=v1.a
)
select * from t1;
a
1
2
drop view v1;
drop table t1,t2;
#
# MDEV-11259: recursive CTE with concatenation operation
#
DROP TABLE IF EXISTS edges;
Warnings:
Note	1051	Unknown table 'test.edges'
CREATE TABLE edges(
a int(10) unsigned NOT NULL,
b int(10) unsigned NOT NULL,
PRIMARY KEY (a,b),
KEY b(b)
);
INSERT INTO edges
VALUES (1,3),(2,1),(2,4),(3,4),(3,5),(3,6),(4,7),(5,1),(5,6),(6,1);
DROP TABLE IF EXISTS edges2;
Warnings:
Note	1051	Unknown table 'test.edges2'
CREATE VIEW edges2 (a, b) AS 
SELECT a, b FROM edges   UNION ALL   SELECT b, a FROM edges;
WITH RECURSIVE transitive_closure(a, b, distance, path_string) AS
( SELECT a, b, 1 AS distance,
concat(a, '.', b, '.') AS path_string
FROM edges
UNION ALL
SELECT tc.a, e.b, tc.distance + 1,
concat(tc.path_string, e.b, '.') AS path_string
FROM edges AS e
JOIN transitive_closure AS tc
ON e.a = tc.b
WHERE tc.path_string NOT LIKE concat('%', e.b, '.%')
)
SELECT * FROM transitive_closure
ORDER BY a, b, distance;
a	b	distance	path_string
1	3	1	1.3.
1	4	2	1.3.4.
1	5	2	1.3.5.
1	6	2	1.3.6.
1	6	3	1.3.5.6.
1	7	3	1.3.4.7.
2	1	1	2.1.
2	3	2	2.1.3.
2	4	1	2.4.
2	4	3	2.1.3.4.
2	5	3	2.1.3.5.
2	6	3	2.1.3.6.
2	6	4	2.1.3.5.6.
2	7	2	2.4.7.
2	7	4	2.1.3.4.7.
3	1	2	3.5.1.
3	1	2	3.6.1.
3	1	3	3.5.6.1.
3	4	1	3.4.
3	5	1	3.5.
3	6	1	3.6.
3	6	2	3.5.6.
3	7	2	3.4.7.
4	7	1	4.7.
5	1	1	5.1.
5	1	2	5.6.1.
5	3	2	5.1.3.
5	3	3	5.6.1.3.
5	4	3	5.1.3.4.
5	4	4	5.6.1.3.4.
5	6	1	5.6.
5	6	3	5.1.3.6.
5	7	4	5.1.3.4.7.
5	7	5	5.6.1.3.4.7.
6	1	1	6.1.
6	3	2	6.1.3.
6	4	3	6.1.3.4.
6	5	3	6.1.3.5.
6	7	4	6.1.3.4.7.
WITH RECURSIVE transitive_closure(a, b, distance, path_string) AS
( SELECT a, b, 1 AS distance,
concat(a, '.', b, '.') AS path_string
FROM edges
WHERE a = 1 -- source
UNION ALL
SELECT tc.a, e.b, tc.distance + 1,
concat(tc.path_string, e.b, '.') AS path_string
FROM edges AS e
JOIN transitive_closure AS tc ON e.a = tc.b
WHERE tc.path_string NOT LIKE concat('%', e.b, '.%')
)
SELECT * FROM transitive_closure
WHERE b = 6 -- destination
ORDER BY a, b, distance;
a	b	distance	path_string
1	6	2	1.3.6.
1	6	3	1.3.5.6.
WITH RECURSIVE transitive_closure(a, b, distance, path_string) AS
( SELECT  a, b, 1 AS distance,
concat(a, '.', b, '.') AS path_string
FROM edges2
UNION ALL
SELECT tc.a, e.b, tc.distance + 1,
concat(tc.path_string, e.b, '.') AS path_string
FROM edges2 AS e
JOIN transitive_closure AS tc ON e.a = tc.b
WHERE tc.path_string NOT LIKE concat('%', e.b, '.%')
)
SELECT * FROM transitive_closure
ORDER BY a, b, distance;
a	b	distance	path_string
1	2	1	1.2.
1	2	3	1.3.4.2.
1	2	4	1.5.3.4.2.
1	2	4	1.6.3.4.2.
1	2	5	1.5.6.3.4.2.
1	2	5	1.6.5.3.4.2.
1	3	1	1.3.
1	3	2	1.5.3.
1	3	2	1.6.3.
1	3	3	1.2.4.3.
1	3	3	1.5.6.3.
1	3	3	1.6.5.3.
1	4	2	1.2.4.
1	4	2	1.3.4.
1	4	3	1.5.3.4.
1	4	3	1.6.3.4.
1	4	4	1.5.6.3.4.
1	4	4	1.6.5.3.4.
1	5	1	1.5.
1	5	2	1.3.5.
1	5	2	1.6.5.
1	5	3	1.3.6.5.
1	5	3	1.6.3.5.
1	5	4	1.2.4.3.5.
1	5	5	1.2.4.3.6.5.
1	6	1	1.6.
1	6	2	1.3.6.
1	6	2	1.5.6.
1	6	3	1.3.5.6.
1	6	3	1.5.3.6.
1	6	4	1.2.4.3.6.
1	6	5	1.2.4.3.5.6.
1	7	3	1.2.4.7.
1	7	3	1.3.4.7.
1	7	4	1.5.3.4.7.
1	7	4	1.6.3.4.7.
1	7	5	1.5.6.3.4.7.
1	7	5	1.6.5.3.4.7.
2	1	1	2.1.
2	1	3	2.4.3.1.
2	1	4	2.4.3.5.1.
2	1	4	2.4.3.6.1.
2	1	5	2.4.3.5.6.1.
2	1	5	2.4.3.6.5.1.
2	3	2	2.1.3.
2	3	2	2.4.3.
2	3	3	2.1.5.3.
2	3	3	2.1.6.3.
2	3	4	2.1.5.6.3.
2	3	4	2.1.6.5.3.
2	4	1	2.4.
2	4	3	2.1.3.4.
2	4	4	2.1.5.3.4.
2	4	4	2.1.6.3.4.
2	4	5	2.1.5.6.3.4.
2	4	5	2.1.6.5.3.4.
2	5	2	2.1.5.
2	5	3	2.1.3.5.
2	5	3	2.1.6.5.
2	5	3	2.4.3.5.
2	5	4	2.1.3.6.5.
2	5	4	2.1.6.3.5.
2	5	4	2.4.3.1.5.
2	5	4	2.4.3.6.5.
2	5	5	2.4.3.1.6.5.
2	5	5	2.4.3.6.1.5.
2	6	2	2.1.6.
2	6	3	2.1.3.6.
2	6	3	2.1.5.6.
2	6	3	2.4.3.6.
2	6	4	2.1.3.5.6.
2	6	4	2.1.5.3.6.
2	6	4	2.4.3.1.6.
2	6	4	2.4.3.5.6.
2	6	5	2.4.3.1.5.6.
2	6	5	2.4.3.5.1.6.
2	7	2	2.4.7.
2	7	4	2.1.3.4.7.
2	7	5	2.1.5.3.4.7.
2	7	5	2.1.6.3.4.7.
2	7	6	2.1.5.6.3.4.7.
2	7	6	2.1.6.5.3.4.7.
3	1	1	3.1.
3	1	2	3.5.1.
3	1	2	3.6.1.
3	1	3	3.4.2.1.
3	1	3	3.5.6.1.
3	1	3	3.6.5.1.
3	2	2	3.1.2.
3	2	2	3.4.2.
3	2	3	3.5.1.2.
3	2	3	3.6.1.2.
3	2	4	3.5.6.1.2.
3	2	4	3.6.5.1.2.
3	4	1	3.4.
3	4	3	3.1.2.4.
3	4	4	3.5.1.2.4.
3	4	4	3.6.1.2.4.
3	4	5	3.5.6.1.2.4.
3	4	5	3.6.5.1.2.4.
3	5	1	3.5.
3	5	2	3.1.5.
3	5	2	3.6.5.
3	5	3	3.1.6.5.
3	5	3	3.6.1.5.
3	5	4	3.4.2.1.5.
3	5	5	3.4.2.1.6.5.
3	6	1	3.6.
3	6	2	3.1.6.
3	6	2	3.5.6.
3	6	3	3.1.5.6.
3	6	3	3.5.1.6.
3	6	4	3.4.2.1.6.
3	6	5	3.4.2.1.5.6.
3	7	2	3.4.7.
3	7	4	3.1.2.4.7.
3	7	5	3.5.1.2.4.7.
3	7	5	3.6.1.2.4.7.
3	7	6	3.5.6.1.2.4.7.
3	7	6	3.6.5.1.2.4.7.
4	1	2	4.2.1.
4	1	2	4.3.1.
4	1	3	4.3.5.1.
4	1	3	4.3.6.1.
4	1	4	4.3.5.6.1.
4	1	4	4.3.6.5.1.
4	2	1	4.2.
4	2	3	4.3.1.2.
4	2	4	4.3.5.1.2.
4	2	4	4.3.6.1.2.
4	2	5	4.3.5.6.1.2.
4	2	5	4.3.6.5.1.2.
4	3	1	4.3.
4	3	3	4.2.1.3.
4	3	4	4.2.1.5.3.
4	3	4	4.2.1.6.3.
4	3	5	4.2.1.5.6.3.
4	3	5	4.2.1.6.5.3.
4	5	2	4.3.5.
4	5	3	4.2.1.5.
4	5	3	4.3.1.5.
4	5	3	4.3.6.5.
4	5	4	4.2.1.3.5.
4	5	4	4.2.1.6.5.
4	5	4	4.3.1.6.5.
4	5	4	4.3.6.1.5.
4	5	5	4.2.1.3.6.5.
4	5	5	4.2.1.6.3.5.
4	6	2	4.3.6.
4	6	3	4.2.1.6.
4	6	3	4.3.1.6.
4	6	3	4.3.5.6.
4	6	4	4.2.1.3.6.
4	6	4	4.2.1.5.6.
4	6	4	4.3.1.5.6.
4	6	4	4.3.5.1.6.
4	6	5	4.2.1.3.5.6.
4	6	5	4.2.1.5.3.6.
4	7	1	4.7.
5	1	1	5.1.
5	1	2	5.3.1.
5	1	2	5.6.1.
5	1	3	5.3.6.1.
5	1	3	5.6.3.1.
5	1	4	5.3.4.2.1.
5	1	5	5.6.3.4.2.1.
5	2	2	5.1.2.
5	2	3	5.3.1.2.
5	2	3	5.3.4.2.
5	2	3	5.6.1.2.
5	2	4	5.1.3.4.2.
5	2	4	5.3.6.1.2.
5	2	4	5.6.3.1.2.
5	2	4	5.6.3.4.2.
5	2	5	5.1.6.3.4.2.
5	2	5	5.6.1.3.4.2.
5	3	1	5.3.
5	3	2	5.1.3.
5	3	2	5.6.3.
5	3	3	5.1.6.3.
5	3	3	5.6.1.3.
5	3	4	5.1.2.4.3.
5	3	5	5.6.1.2.4.3.
5	4	2	5.3.4.
5	4	3	5.1.2.4.
5	4	3	5.1.3.4.
5	4	3	5.6.3.4.
5	4	4	5.1.6.3.4.
5	4	4	5.3.1.2.4.
5	4	4	5.6.1.2.4.
5	4	4	5.6.1.3.4.
5	4	5	5.3.6.1.2.4.
5	4	5	5.6.3.1.2.4.
5	6	1	5.6.
5	6	2	5.1.6.
5	6	2	5.3.6.
5	6	3	5.1.3.6.
5	6	3	5.3.1.6.
5	6	5	5.1.2.4.3.6.
5	6	5	5.3.4.2.1.6.
5	7	3	5.3.4.7.
5	7	4	5.1.2.4.7.
5	7	4	5.1.3.4.7.
5	7	4	5.6.3.4.7.
5	7	5	5.1.6.3.4.7.
5	7	5	5.3.1.2.4.7.
5	7	5	5.6.1.2.4.7.
5	7	5	5.6.1.3.4.7.
5	7	6	5.3.6.1.2.4.7.
5	7	6	5.6.3.1.2.4.7.
6	1	1	6.1.
6	1	2	6.3.1.
6	1	2	6.5.1.
6	1	3	6.3.5.1.
6	1	3	6.5.3.1.
6	1	4	6.3.4.2.1.
6	1	5	6.5.3.4.2.1.
6	2	2	6.1.2.
6	2	3	6.3.1.2.
6	2	3	6.3.4.2.
6	2	3	6.5.1.2.
6	2	4	6.1.3.4.2.
6	2	4	6.3.5.1.2.
6	2	4	6.5.3.1.2.
6	2	4	6.5.3.4.2.
6	2	5	6.1.5.3.4.2.
6	2	5	6.5.1.3.4.2.
6	3	1	6.3.
6	3	2	6.1.3.
6	3	2	6.5.3.
6	3	3	6.1.5.3.
6	3	3	6.5.1.3.
6	3	4	6.1.2.4.3.
6	3	5	6.5.1.2.4.3.
6	4	2	6.3.4.
6	4	3	6.1.2.4.
6	4	3	6.1.3.4.
6	4	3	6.5.3.4.
6	4	4	6.1.5.3.4.
6	4	4	6.3.1.2.4.
6	4	4	6.5.1.2.4.
6	4	4	6.5.1.3.4.
6	4	5	6.3.5.1.2.4.
6	4	5	6.5.3.1.2.4.
6	5	1	6.5.
6	5	2	6.1.5.
6	5	2	6.3.5.
6	5	3	6.1.3.5.
6	5	3	6.3.1.5.
6	5	5	6.1.2.4.3.5.
6	5	5	6.3.4.2.1.5.
6	7	3	6.3.4.7.
6	7	4	6.1.2.4.7.
6	7	4	6.1.3.4.7.
6	7	4	6.5.3.4.7.
6	7	5	6.1.5.3.4.7.
6	7	5	6.3.1.2.4.7.
6	7	5	6.5.1.2.4.7.
6	7	5	6.5.1.3.4.7.
6	7	6	6.3.5.1.2.4.7.
6	7	6	6.5.3.1.2.4.7.
7	1	3	7.4.2.1.
7	1	3	7.4.3.1.
7	1	4	7.4.3.5.1.
7	1	4	7.4.3.6.1.
7	1	5	7.4.3.5.6.1.
7	1	5	7.4.3.6.5.1.
7	2	2	7.4.2.
7	2	4	7.4.3.1.2.
7	2	5	7.4.3.5.1.2.
7	2	5	7.4.3.6.1.2.
7	2	6	7.4.3.5.6.1.2.
7	2	6	7.4.3.6.5.1.2.
7	3	2	7.4.3.
7	3	4	7.4.2.1.3.
7	3	5	7.4.2.1.5.3.
7	3	5	7.4.2.1.6.3.
7	3	6	7.4.2.1.5.6.3.
7	3	6	7.4.2.1.6.5.3.
7	4	1	7.4.
7	5	3	7.4.3.5.
7	5	4	7.4.2.1.5.
7	5	4	7.4.3.1.5.
7	5	4	7.4.3.6.5.
7	5	5	7.4.2.1.3.5.
7	5	5	7.4.2.1.6.5.
7	5	5	7.4.3.1.6.5.
7	5	5	7.4.3.6.1.5.
7	5	6	7.4.2.1.3.6.5.
7	5	6	7.4.2.1.6.3.5.
7	6	3	7.4.3.6.
7	6	4	7.4.2.1.6.
7	6	4	7.4.3.1.6.
7	6	4	7.4.3.5.6.
7	6	5	7.4.2.1.3.6.
7	6	5	7.4.2.1.5.6.
7	6	5	7.4.3.1.5.6.
7	6	5	7.4.3.5.1.6.
7	6	6	7.4.2.1.3.5.6.
7	6	6	7.4.2.1.5.3.6.
WITH RECURSIVE transitive_closure(a, b, distance, path_string)
AS
( SELECT a, b, 1 AS distance,
concat(a, '.', b, '.') AS path_string
FROM edges2
UNION ALL
SELECT tc.a, e.b, tc.distance + 1,
concat(tc.path_string, e.b, '.') AS path_string
FROM edges2 AS e
JOIN transitive_closure AS tc ON e.a = tc.b
WHERE tc.path_string NOT LIKE concat('%', e.b, '.%')
)
SELECT a, b, min(distance) AS dist FROM transitive_closure
GROUP BY a, b
ORDER BY a, dist, b;
a	b	dist
1	2	1
1	3	1
1	4	2
1	5	1
1	6	1
1	7	3
2	1	1
2	3	2
2	4	1
2	5	2
2	6	2
2	7	2
3	1	1
3	2	2
3	4	1
3	5	1
3	6	1
3	7	2
4	1	2
4	2	1
4	3	1
4	5	2
4	6	2
4	7	1
5	1	1
5	2	2
5	3	1
5	4	2
5	6	1
5	7	3
6	1	1
6	2	2
6	3	1
6	4	2
6	5	1
6	7	3
7	1	3
7	2	2
7	3	2
7	4	1
7	5	3
7	6	3
DROP VIEW edges2;
DROP TABLE edges;
#
# MDEV-11674: recursive CTE table that cannot be stored
#             in a heap table
#
create table t1 (id int, test_data varchar(36));
insert into t1(id, test_data)
select id, test_data
from (
with recursive data_generator(id, test_data) as (
select 1 as id, uuid() as test_data
union all
select id + 1, uuid() from data_generator where id < 150000
)
select * from data_generator
) as a;
drop table t1;
#
# MDEV-10773: ANALYZE for query with recursive CTE
#
analyze format=json 
with recursive src(counter) as 
(select 1 
union 
select counter+1 from src where counter<10
) select * from src;
ANALYZE
{
  "query_block": {
    "select_id": 1,
    "r_loops": 1,
    "r_total_time_ms": "REPLACED",
    "table": {
      "table_name": "<derived2>",
      "access_type": "ALL",
      "r_loops": 1,
      "rows": 2,
      "r_rows": 10,
      "r_total_time_ms": "REPLACED",
      "filtered": 100,
      "r_filtered": 100,
      "materialized": {
        "query_block": {
          "recursive_union": {
            "table_name": "<union2,3>",
            "access_type": "ALL",
            "r_loops": 0,
            "r_rows": null,
            "query_specifications": [
              {
                "query_block": {
                  "select_id": 2,
                  "table": {
                    "message": "No tables used"
                  }
                }
              },
              {
                "query_block": {
                  "select_id": 3,
                  "r_loops": 10,
                  "r_total_time_ms": "REPLACED",
                  "table": {
                    "table_name": "<derived2>",
                    "access_type": "ALL",
                    "r_loops": 10,
                    "rows": 2,
                    "r_rows": 1,
                    "r_total_time_ms": "REPLACED",
                    "filtered": 100,
                    "r_filtered": 90,
                    "attached_condition": "src.counter < 10"
                  }
                }
              }
            ]
          }
        }
      }
    }
  }
}
#
# mdev-12360: recursive reference in left operand of LEFT JOIN
#
create table  folks(id int, name char(32), dob date, father int, mother int);
insert into folks values
(100, 'Me', '2000-01-01', 20, 30),
(20, 'Dad', '1970-02-02', 10, 9),
(30, 'Mom', '1975-03-03', 8, 7),
(10, 'Grandpa Bill', '1940-04-05', null, null),
(9, 'Grandma Ann', '1941-10-15', null, null),
(25, 'Uncle Jim', '1968-11-18', 8, 7),
(98, 'Sister Amy', '2001-06-20', 20, 30),
(7, 'Grandma Sally', '1943-08-23', null, 6),
(8, 'Grandpa Ben', '1940-10-21', null, null),
(6, 'Grandgrandma Martha', '1923-05-17', null, null),
(67, 'Cousin Eddie', '1992-02-28', 25, 27),
(27, 'Auntie Melinda', '1971-03-29', null, null);
with recursive
ancestor_ids (id)
as
(
select father from folks where name = 'Me'
  union
select mother from folks where name = 'Me'
  union
select father from ancestor_ids as a left join folks on folks.id = a.id
union
select mother from ancestor_ids as a left join folks on folks.id = a.id
),
ancestors 
as
(
select p.* from folks as p, ancestor_ids as a
where p.id = a.id
)
select * from ancestors;
id	name	dob	father	mother
20	Dad	1970-02-02	10	9
30	Mom	1975-03-03	8	7
10	Grandpa Bill	1940-04-05	NULL	NULL
9	Grandma Ann	1941-10-15	NULL	NULL
7	Grandma Sally	1943-08-23	NULL	6
8	Grandpa Ben	1940-10-21	NULL	NULL
6	Grandgrandma Martha	1923-05-17	NULL	NULL
drop table folks;
#
# mdev-12368: crash with mutually recursive CTE
#             that arenot Standard compliant 
#
create table value_nodes (v char(4));
create table module_nodes(m char(4));
create table module_arguments(m char(4), v char(4));
create table module_results(m char(4), v char(4));
with recursive
reached_values as 
(
select v from value_nodes where v in ('v3','v7','v9')
union
select module_results.v from module_results, applied_modules
where module_results.m = applied_modules.m
),
applied_modules as
(
select module_nodes.m
from
module_nodes
left join
( 
module_arguments
left join
reached_values
on module_arguments.v = reached_values.v
)
on reached_values.v is null and
module_nodes.m = module_arguments.m
where module_arguments.m is null
)
select * from reached_values;
ERROR HY000: Restrictions imposed on recursive definitions are violated for table 'applied_modules'
drop table value_nodes, module_nodes, module_arguments, module_results;
#
# mdev-12375: query using one of two mutually recursive CTEs
#             whose non-recursive part returns an empty set
#
create table value_nodes (v char(4));
insert into value_nodes values
('v1'), ('v2'), ('v3'), ('v4'), ('v5'), ('v6'), ('v7'), ('v8'), ('v9'),
('v10'), ('v11'), ('v12'), ('v13'), ('v14'), ('v15'), ('v16');
create table module_nodes(m char(4));
insert into module_nodes values
('m1'), ('m2'), ('m3'), ('m4'), ('m5'), ('m6'), ('m7');
create table module_arguments(m char(4), v char(4));
insert into module_arguments values
('m1','v3'), ('m1','v9'),
('m2','v4'), ('m2','v3'), ('m2','v7'),
('m3','v6'),
('m4','v4'), ('m4','v1'),
('m5','v10'), ('m5','v8'), ('m5','v3'),
('m6','v8'), ('m6','v1'),
('m7','v11'), ('m7','v12');
create table module_results(m char(4), v char(4));
insert into module_results values
('m1','v4'),
('m2','v1'), ('m2','v6'),
('m3','v10'),
('m4','v8'),
('m5','v11'), ('m5','v9'),
('m6','v12'), ('m6','v4'),
('m7','v2');
set statement max_recursive_iterations=2, standard_compliant_cte=0 for
with recursive
reached_values as 
(
select v from value_nodes where v in ('v3','v7','v9')
union
select module_results.v from module_results, applied_modules
where module_results.m = applied_modules.m
),
applied_modules as
(
select * from module_nodes where 1=0
union
select module_nodes.m
from
module_nodes
left join
( 
module_arguments
left join
reached_values
on module_arguments.v = reached_values.v
)
on reached_values.v is null and
module_nodes.m = module_arguments.m
where module_arguments.m is null
)
select * from applied_modules;
m
m1
m2
drop table value_nodes, module_nodes, module_arguments, module_results;
#
# mdev-12519: recursive references in subqueries 
#             
create table t1 (lp char(4) not null, rp char(4) not null);
insert into t1 values
('p1','p2'), ('p2','p3'), ('p3','p4'), ('p4','p5'),
('p2','p7'), ('p7','p8'), ('p8','p3'), ('p8','p4');
set standard_compliant_cte=0;
with recursive
reachables(p) as 
( 
select lp from t1 where lp = 'p1'
   union 
select t1.rp from reachables, t1 
where t1.lp = reachables.p
)
select * from reachables;
p
p1
p2
p3
p7
p4
p8
p5
with recursive 
reachables(p) as
(
select lp from t1 where lp = 'p1'
   union 
select t1.rp from reachables, t1 
where 'p3' not in (select * from reachables) and
t1.lp = reachables.p
)
select * from reachables;
p
p1
p2
p3
p7
with recursive 
reachables(p) as
(
select lp from t1 where lp = 'p1'
   union 
select t1.rp from reachables, t1 
where 'p3' not in (select p from reachables where p <= 'p5'
                         union
select p from reachables where p > 'p5') and
t1.lp = reachables.p
)
select * from reachables;
p
p1
p2
p3
p7
prepare stmt from "
with recursive 
reachables(p) as
(
   select lp from t1 where lp = 'p1'
   union 
   select t1.rp from reachables, t1 
      where 'p3' not in (select p from reachables where p <= 'p5'
                         union
                         select p from reachables where p > 'p5') and
                 t1.lp = reachables.p
)
select * from reachables;
";
execute stmt;
p
p1
p2
p3
p7
execute stmt;
p
p1
p2
p3
p7
deallocate prepare stmt;
drop table t1;
create table objects(v char(4) not null);
insert into objects values
('v1'), ('v2'), ('v3'), ('v4'), ('v5'),
('v6'), ('v7'), ('v8'), ('v9'), ('v10');
create table modules(m char(4) not null);
insert into modules values
('m1'), ('m2'), ('m3'), ('m4');
create table module_arguments(m char(4) not null, v char(4) not null);
insert into module_arguments values
('m1','v3'), ('m1','v9'),
('m2','v4'), ('m2','v7'),
('m3','v6'), ('m4','v2');
create table module_results(m char(4) not null, v char(4) not null);
insert into module_results values
('m1','v4'),
('m2','v1'), ('m2','v6'),
('m3','v10'), ('m4','v7');
set standard_compliant_cte=0;
with recursive
reached_objects as 
(
select v, 'init' as m from objects where v in ('v3','v7','v9')
union
select module_results.v, module_results.m from module_results, applied_modules
where module_results.m = applied_modules.m
),
applied_modules as
(
select * from modules where 1=0
union
select modules.m
from
modules
where
not exists (select * from module_arguments
where module_arguments.m = modules.m and
module_arguments.v not in 
(select v from reached_objects))
)
select * from reached_objects;
v	m
v3	init
v7	init
v9	init
v4	m1
v1	m2
v6	m2
v10	m3
with recursive
reached_objects as 
(
select v, 'init' as m from objects where v in ('v3','v7','v9')
union
select module_results.v, module_results.m from module_results, applied_modules
where module_results.m = applied_modules.m
),
applied_modules as
(
select * from modules where 1=0
union
select modules.m
from
modules
where 
'v6' not in (select v from reached_objects) and
not exists (select * from module_arguments
where module_arguments.m = modules.m and
module_arguments.v not in 
(select v from reached_objects))
)
select * from reached_objects;
v	m
v3	init
v7	init
v9	init
v4	m1
v1	m2
v6	m2
prepare stmt from "
with recursive
reached_objects as 
(
  select v, 'init' as m from objects where v in ('v3','v7','v9')
  union
  select module_results.v, module_results.m from module_results, applied_modules
     where module_results.m = applied_modules.m
),
applied_modules as
(
  select * from modules where 1=0
  union
  select modules.m
  from
    modules
    where 
      'v6' not in (select v from reached_objects) and
      not exists (select * from module_arguments
                    where module_arguments.m = modules.m and
                          module_arguments.v not in 
                          (select v from reached_objects))
)
select * from reached_objects;
";
execute stmt;
v	m
v3	init
v7	init
v9	init
v4	m1
v1	m2
v6	m2
execute stmt;
v	m
v3	init
v7	init
v9	init
v4	m1
v1	m2
v6	m2
deallocate prepare stmt;
drop table objects, modules, module_arguments, module_results;
set standard_compliant_cte=default;
select @@standard_compliant_cte;
@@standard_compliant_cte
1
#
# mdev-12554: impossible where in recursive select 
#             
CREATE TABLE t1 (i int);
INSERT INTO t1 VALUES (1),(2);
WITH RECURSIVE
cte(f) AS ( SELECT i FROM t1 UNION SELECT f FROM t1, cte WHERE 1=0 )
SELECT * FROM cte;
f
1
2
DROP TABLE t1;
#
# mdev-12556: recursive execution uses Aria temporary tables 
#             
CREATE TABLE t (c1 varchar(255), c2 tinytext);
INSERT INTO t VALUES ('a','a'),('b','b'),('c','c'),('d','d');
ANALYZE WITH RECURSIVE cte(f) AS (
SELECT c1 FROM t
UNION
SELECT c1 FROM t, cte
) SELECT COUNT(*) FROM cte;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	4	4.00	100.00	100.00	
2	SUBQUERY	t	ALL	NULL	NULL	NULL	NULL	4	4.00	100.00	100.00	
3	RECURSIVE UNION	t	ALL	NULL	NULL	NULL	NULL	4	4.00	100.00	100.00	
3	RECURSIVE UNION	<derived2>	ALL	NULL	NULL	NULL	NULL	4	4.00	100.00	100.00	Using join buffer (flat, BNL join)
NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	0.00	NULL	NULL	
WITH RECURSIVE cte(f) AS (
SELECT c1 FROM t
UNION
SELECT c1 FROM t, cte
) SELECT COUNT(*) FROM cte;
COUNT(*)
4
ANALYZE WITH RECURSIVE cte(f) AS (
SELECT c2 FROM t
UNION
SELECT c2 FROM t, cte
) SELECT COUNT(*) FROM cte;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	4	4.00	100.00	100.00	
2	SUBQUERY	t	ALL	NULL	NULL	NULL	NULL	4	4.00	100.00	100.00	
3	RECURSIVE UNION	t	ALL	NULL	NULL	NULL	NULL	4	4.00	100.00	100.00	
3	RECURSIVE UNION	<derived2>	ALL	NULL	NULL	NULL	NULL	4	4.00	100.00	100.00	Using join buffer (flat, BNL join)
NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	0.00	NULL	NULL	
WITH RECURSIVE cte(f) AS (
SELECT c2 FROM t
UNION
SELECT c2 FROM t, cte
) SELECT COUNT(*) FROM cte;
COUNT(*)
4
DROP TABLE t;
#
# mdev-12563: no recursive references on the top level of the CTE spec 
#  
CREATE TABLE t (i int);
INSERT INTO t VALUES (3), (1),(2);
SET standard_compliant_cte=0;
WITH RECURSIVE cte(f) AS (
SELECT i FROM t
UNION
SELECT i FROM t WHERE i NOT IN ( SELECT * FROM cte )
) SELECT * FROM cte;
f
3
1
2
WITH RECURSIVE cte(f) AS (
SELECT i FROM t
UNION
SELECT i FROM t WHERE i NOT IN ( SELECT * FROM cte WHERE i < 2 )
UNION
SELECT i FROM t WHERE i NOT IN ( SELECT * FROM cte WHERE i > 2 )
) SELECT * FROM cte;
f
3
1
2
WITH RECURSIVE cte(f) AS (
SELECT i FROM t
UNION
SELECT i FROM t
WHERE i NOT IN ( SELECT * FROM cte WHERE i < 2
UNION
SELECT * FROM cte WHERE i > 2)
) SELECT * FROM cte;
f
3
1
2
WITH RECURSIVE cte(f) AS (
SELECT i FROM t
UNION
SELECT i FROM t 
WHERE i NOT IN ( SELECT * FROM t
WHERE i IN ( SELECT * FROM cte ) GROUP BY i )
) SELECT * FROM cte;
f
3
1
2
WITH RECURSIVE cte(f) AS (
SELECT i FROM t
UNION
SELECT i FROM t WHERE i NOT IN ( SELECT * FROM cte )
UNION 
SELECT * FROM cte WHERE f > 2
) SELECT * FROM cte;
f
3
1
2
set standard_compliant_cte=default;
DROP TABLE t;