#
# MariaDB tests for EXPLAIN UPDATE/DELETE.
#
--disable_warnings
drop table if exists t0, t1;
--enable_warnings

create table t0 (a int) engine=myisam;
insert into t0 values (1),(2),(3),(4),(5),(6),(7),(8);

--echo #
--echo #  Tests for single-table DELETE
--echo # 

explain select * from t0 where a=3;
explain delete from t0 where a=3;

--echo # DELETE without WHERE is a special case:
explain delete from t0;

create table t1 (a int, b int, filler char(100), key(a), key(b));
insert into t1 
select A.a+10*B.a + 10*C.a, A.a+10*B.a + 10*C.a, 'filler' 
from t0 A, t0 B, t0 C;

--echo # This should use an index,  possible_keys=NULL because there is no WHERE
explain delete from t1 order by a limit 2;

--echo # This should use range, possible_keys={a,b}
explain delete from t1 where a<20 and b < 10;

--echo # This should use ALL + filesort
explain delete from t1 order by a+1 limit 2;

--echo # This should use range + using filesort
explain delete from t1 where a<20 order by b limit 2;

--echo # Try some subqueries:
explain delete from t1 where a < (select max(a) from t0);
explain delete from t1 where a < (select max(a) from t0 where a < t1.b);

--echo #
--echo #  Tests for multi-table DELETE
--echo # 
explain delete t1 from t0, t1 where t0.a = t1.a;
drop table t0, t1;

--echo # ###################################################################
--echo # ## EXPLAIN UPDATE tests
--echo # ###################################################################
create table t0 (a int) engine=myisam;
insert into t0 values (1),(2),(3),(4),(5),(6),(7),(8);

explain update t0 set a=3 where a=4;

create table t1 (a int, b int, filler char(100), key(a), key(b));
insert into t1 
select A.a+10*B.a + 10*C.a, A.a+10*B.a + 10*C.a, 'filler' 
from t0 A, t0 B, t0 C;

explain update t1 set a=a+1 where 3>4;
explain update t1 set a=a+1 where a=3 and a=4;

--echo # This should use an index,  possible_keys=NULL because there is no WHERE
explain update t1 set a=a+1 order by a limit 2;

--echo # This should use range, possible_keys={a,b}
explain update t1 set filler='fooo' where a<20 and b < 10;

--echo # This should use ALL + filesort
explain update t1 set filler='fooo' order by a+1 limit 2;

--echo # This should use range + using filesort
explain update t1 set filler='fooo' where a<20 order by b limit 2;

--echo # Try some subqueries:
explain update t1 set filler='fooo' where a < (select max(a) from t0);
explain update t1 set filler='fooo' where a < (select max(a) from t0 where a < t1.b);

--echo #
--echo #  Tests for multi-table UPDATE
--echo # 
explain update t0, t1 set t1.a=t1.a+1 where t0.a = t1.a;


drop table t0, t1;

--echo #
--echo # Try DELETE ... RETURNING ...
--echo #
create table t0 (a int);
insert into t0 values (1),(2),(3),(4);
explain delete from t0 where a=1 returning a;
explain delete from t0 returning a;
drop table t0;

--echo #
--echo # MDEV-5070 - EXPLAIN INSERT ... SELECT crashes on 10.0-base-explain-slowquerylog
--echo #
create table t0 (a int);
insert into t0 values (1),(2),(3),(4),(5),(6),(7),(8);
create table t1 (a int);

explain insert into t1 select * from t0;
explain replace into t1 select * from t0;

drop table t0, t1;