2002-04-26 07:56:28 +02:00
drop table if exists t1;
select IF(0,"ERROR","this"),IF(1,"is","ERROR"),IF(NULL,"ERROR","a"),IF(1,2,3)|0,IF(1,2.0,3.0)+0 ;
2002-04-22 22:41:55 +02:00
IF(0,"ERROR","this") IF(1,"is","ERROR") IF(NULL,"ERROR","a") IF(1,2,3)|0 IF(1,2.0,3.0)+0
this is a 2 2.0
2003-12-10 05:31:42 +01:00
CREATE TABLE t1 (st varchar(255) NOT NULL, u int(11) NOT NULL) ENGINE=MyISAM;
2002-04-26 07:56:28 +02:00
INSERT INTO t1 VALUES ('a',1),('A',1),('aa',1),('AA',1),('a',1),('aaa',0),('BBB',0);
select if(1,st,st) s from t1 order by s;
2002-04-22 22:41:55 +02:00
s
a
A
a
aa
AA
aaa
BBB
2002-04-26 07:56:28 +02:00
select if(u=1,st,st) s from t1 order by s;
2002-04-22 22:41:55 +02:00
s
a
A
a
aa
AA
aaa
BBB
2002-04-26 07:56:28 +02:00
select if(u=1,binary st,st) s from t1 order by s;
2002-04-22 22:41:55 +02:00
s
A
AA
BBB
a
a
aa
aaa
2002-04-26 07:56:28 +02:00
select if(u=1,st,binary st) s from t1 where st like "%a%" order by s;
2002-04-22 22:41:55 +02:00
s
A
AA
a
a
aa
aaa
2003-10-30 11:57:26 +01:00
explain extended select if(u=1,st,binary st) s from t1 where st like "%a%" order by s;
2006-07-28 19:27:01 +02:00
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 7 100.00 Using where; Using filesort
2003-10-30 11:57:26 +01:00
Warnings:
2016-11-27 19:50:10 +01:00
Note 1003 select if(`test`.`t1`.`u` = 1,`test`.`t1`.`st`,cast(`test`.`t1`.`st` as char charset binary)) AS `s` from `test`.`t1` where `test`.`t1`.`st` like '%a%' order by if(`test`.`t1`.`u` = 1,`test`.`t1`.`st`,cast(`test`.`t1`.`st` as char charset binary))
2005-04-01 14:04:50 +02:00
select nullif(u, 1) from t1;
nullif(u, 1)
2003-10-30 11:57:26 +01:00
NULL
NULL
NULL
NULL
NULL
2005-04-01 14:04:50 +02:00
0
0
explain extended select nullif(u, 1) from t1;
2006-07-28 19:27:01 +02:00
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 7 100.00
2003-10-30 11:57:26 +01:00
Warnings:
2005-04-01 14:04:50 +02:00
Note 1003 select nullif(`test`.`t1`.`u`,1) AS `nullif(u, 1)` from `test`.`t1`
2002-04-26 07:56:28 +02:00
drop table t1;
2005-04-01 14:04:50 +02:00
select nullif(1,'test');
nullif(1,'test')
1
Warnings:
Warning 1292 Truncated incorrect DOUBLE value: 'test'
2004-03-16 08:33:03 +01:00
select NULLIF(NULL,NULL), NULLIF(NULL,1), NULLIF(NULL,1.0), NULLIF(NULL,"test");
NULLIF(NULL,NULL) NULLIF(NULL,1) NULLIF(NULL,1.0) NULLIF(NULL,"test")
NULL NULL NULL NULL
select NULLIF(1,NULL), NULLIF(1.0, NULL), NULLIF("test", NULL);
NULLIF(1,NULL) NULLIF(1.0, NULL) NULLIF("test", NULL)
1 1.0 test
2002-04-26 07:56:28 +02:00
create table t1 (num double(12,2));
insert into t1 values (144.54);
select sum(if(num is null,0.00,num)) from t1;
2002-04-22 22:41:55 +02:00
sum(if(num is null,0.00,num))
2002-04-26 07:56:28 +02:00
144.54
drop table t1;
2002-08-12 06:02:08 +02:00
create table t1 (x int, y int);
insert into t1 values (0,6),(10,16),(20,26),(30,10),(40,46),(50,56);
select min(if(y -x > 5,y,NULL)), max(if(y - x > 5,y,NULL)) from t1;
min(if(y -x > 5,y,NULL)) max(if(y - x > 5,y,NULL))
6 56
drop table t1;
2004-06-07 12:38:35 +02:00
create table t1 (a int);
insert t1 values (1),(2);
select if(1>2,a,avg(a)) from t1;
if(1>2,a,avg(a))
1.5000
drop table t1;
2004-09-18 11:06:44 +02:00
SELECT NULLIF(5,5) IS NULL, NULLIF(5,5) IS NOT NULL;
NULLIF(5,5) IS NULL NULLIF(5,5) IS NOT NULL
1 0
2005-06-02 15:00:07 +02:00
CREATE TABLE `t1` (
`id` int(11) NOT NULL ,
`date` int(10) default NULL,
`text` varchar(32) NOT NULL
);
INSERT INTO t1 VALUES (1,1110000000,'Day 1'),(2,1111000000,'Day 2'),(3,1112000000,'Day 3');
SELECT id, IF(date IS NULL, '-', FROM_UNIXTIME(date, '%d-%m-%Y')) AS date_ord, text FROM t1 ORDER BY date_ord ASC;
id date_ord text
1 05-03-2005 Day 1
2 16-03-2005 Day 2
3 28-03-2005 Day 3
SELECT id, IF(date IS NULL, '-', FROM_UNIXTIME(date, '%d-%m-%Y')) AS date_ord, text FROM t1 ORDER BY date_ord DESC;
id date_ord text
3 28-03-2005 Day 3
2 16-03-2005 Day 2
1 05-03-2005 Day 1
DROP TABLE t1;
2005-06-13 20:24:26 +02:00
CREATE TABLE t1 (a CHAR(10));
INSERT INTO t1 VALUES ('aaa'), (NULL), (''), ('bbb');
SELECT a, NULLIF(a,'') FROM t1;
a NULLIF(a,'')
aaa aaa
NULL NULL
NULL
bbb bbb
SELECT a, NULLIF(a,'') FROM t1 WHERE NULLIF(a,'') IS NULL;
a NULLIF(a,'')
NULL NULL
NULL
DROP TABLE t1;
2006-02-14 14:22:37 +01:00
create table t1 (f1 int, f2 int);
insert into t1 values(1,1),(0,0);
select f1, f2, if(f1, 40.0, 5.00) from t1 group by f1 order by f2;
f1 f2 if(f1, 40.0, 5.00)
0 0 5.00
1 1 40.00
drop table t1;
Bug#24532 (The return data type of IS TRUE is different from similar
operations)
Before this change, the boolean predicates:
- X IS TRUE,
- X IS NOT TRUE,
- X IS FALSE,
- X IS NOT FALSE
were implemented by expanding the Item tree in the parser, by using a
construct like:
Item_func_if(Item_func_ifnull(X, <value>), <value>, <value>)
Each <value> was a constant integer, either 0 or 1.
A bug in the implementation of the function IF(a, b, c), in
Item_func_if::fix_length_and_dec(), would cause the following :
When the arguments b and c are both unsigned, the result type of the
function was signed, instead of unsigned.
When the result of the if function is signed, space for the sign could be
counted twice (in the max() expression for a signed argument, and in the
total), causing the member max_length to be too high.
An effect of this is that the final type of IF(x, int(1), int(1)) would be
int(2) instead of int(1).
With this fix, the problems found in Item_func_if::fix_length_and_dec()
have been fixed.
While it's semantically correct to represent 'X IS TRUE' with
Item_func_if(Item_func_ifnull(X, <value>), <value>, <value>),
there are however more problems with this construct.
a)
Building the parse tree involves :
- creating 5 Item instances (3 ints, 1 ifnull, 1 if),
- creating each Item calls my_pthread_getspecific_ptr() once in the operator
new(size), and a second time in the Item::Item() constructor, resulting
in a total of 10 calls to get the current thread.
Evaluating the expression involves evaluating up to 4 nodes at runtime.
This representation could be greatly simplified and improved.
b)
Transforming the parse tree internally with if(ifnull(...)) is fine as long
as this transformation is internal to the server implementation.
With views however, the result of the parse tree is later exposed by the
::print() functions, and stored as part of the view definition.
Doing this has long term consequences:
1)
The original semantic 'X IS TRUE' is lost, and replaced by the
if(ifnull(...)) expression. As a result, SHOW CREATE VIEW does not restore
the original code.
2)
Should a future version of MySQL implement the SQL BOOLEAN data type for
example, views created today using 'X IS NULL' can be exported using
mysqldump, and imported again. Such views would be converted correctly and
automatically to use a BOOLEAN column in the future version.
With 'X IS TRUE' and the current implementations, views using these
"boolean" predicates would not be converted during the export/import, and
would use integer columns instead.
The difference traces back to how SHOW CREATE VIEW preserves 'X IS NULL' but
does not preserve the 'X IS TRUE' semantic.
With this fix, internal representation of 'X IS TRUE' booleans predicates
has changed, so that:
- dedicated Item classes are created for each predicate,
- only 1 Item is created to represent 1 predicate
- my_pthread_getspecific_ptr() is invoked 1 time instead of 10
- SHOW CREATE VIEW preserves the original semantic, and prints 'X IS TRUE'.
Note that, because of the fix in Item_func_if, views created before this fix
will:
- correctly use a int(1) type instead of int(2) for boolean predicates,
- incorrectly print the if(ifnull(...), ...) expression in SHOW CREATE VIEW,
since the original semantic (X IS TRUE) has been lost.
- except for the syntax used in SHOW CREATE VIEW, these views will operate
properly, no action is needed.
Views created after this fix will operate correctly, and will preserve the
original code semantic in SHOW CREATE VIEW.
mysql-test/r/func_if.result:
IF(x, unsigned, unsigned) should be unsigned.
mysql-test/r/view.result:
Preserve the semantic of 'X IS [NOT] (TRUE|FALSE)' boolean predicates.
mysql-test/t/func_if.test:
IF(x, unsigned, unsigned) should be unsigned.
mysql-test/t/view.test:
Preserve the semantic of 'X IS [NOT] (TRUE|FALSE)' boolean predicates.
sql/item_cmpfunc.cc:
Preserve the semantic of 'X IS [NOT] (TRUE|FALSE)' boolean predicates.
IF(x, unsigned, unsigned) should be unsigned.
sql/item_cmpfunc.h:
Preserve the semantic of 'X IS [NOT] (TRUE|FALSE)' boolean predicates.
sql/sql_yacc.yy:
Preserve the semantic of 'X IS [NOT] (TRUE|FALSE)' boolean predicates.
2007-02-12 21:59:29 +01:00
select if(0, 18446744073709551610, 18446744073709551610);
if(0, 18446744073709551610, 18446744073709551610)
18446744073709551610
2008-07-30 13:07:37 +02:00
CREATE TABLE t1(a DECIMAL(10,3));
SELECT t1.a,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,0)))))))))))))))))))))))))))))) + 1
FROM t1;
a IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((R
DROP TABLE t1;
2008-12-12 14:16:25 +01:00
CREATE TABLE t1 (c LONGTEXT);
2011-06-09 17:23:39 +02:00
INSERT INTO t1 VALUES(1), (2), (3), (4), ('1234567890123456789');
SELECT IF(1, CAST(c AS UNSIGNED), 0) FROM t1;
IF(1, CAST(c AS UNSIGNED), 0)
1
2
3
4
1234567890123456789
2008-12-12 14:16:25 +01:00
SELECT * FROM (SELECT MAX(IF(1, CAST(c AS UNSIGNED), 0)) FROM t1) AS te;
MAX(IF(1, CAST(c AS UNSIGNED), 0))
2011-06-09 17:23:39 +02:00
1234567890123456789
2008-12-12 14:16:25 +01:00
SELECT * FROM (SELECT MAX(IFNULL(CAST(c AS UNSIGNED), 0)) FROM t1) AS te;
MAX(IFNULL(CAST(c AS UNSIGNED), 0))
2011-06-09 17:23:39 +02:00
1234567890123456789
2008-12-12 14:16:25 +01:00
DROP TABLE t1;
2008-07-30 13:07:37 +02:00
End of 5.0 tests
Bug#55077: Assertion failed: width > 0 && to != ((void *)0),
file .\dtoa.c
The assertion failure was correct because the 'width' argument
of my_gcvt() has the signed integer type, whereas the unsigned
value UINT_MAX32 was being passed by the caller
(Field_double::val_str()) leading to a negative width in
my_gcvt().
The following chain of problems was found by further analysis:
1. The display width for a floating point number is calculated
in Field_double::val_str() as either field_length or the
maximum possible length of string representation of a floating
point number, whichever is greater. Since in the bug's test
case field_length is UINT_MAX32, we get the same value as the
display width. This does not make any sense because for numeric
values field_length only matters for ZEROFILL columns,
otherwise it does not make sense to allocate that much memory
just to print a number. Field_float::val_str() has a similar
problem.
2. Even if the above wasn't the case, we would still get a
crash on a slightly different test case when trying to allocate
UINT_MAX32 bytes with String::alloc() because the latter does
not handle such large input values correctly due to alignment
overflows.
3. Even when String::alloc() is fixed to return an error when
an alignment overflow occurs, there is still a problem because
almost no callers check its return value, and
Field_double::val_str() is not an exception (same for
Field_float::val_str()).
4. Even if all of the above wasn't the case, creating a
Field_double object with UINT_MAX32 as its field_length does
not make much sense either, since the .frm code limits it to
MAX_FIELD_CHARLENGTH (255) bytes. Such a beast can only be
created by create_tmp_field_from_item() from an Item with
REAL_RESULT as its result_type() and UINT_MAX32 as its
max_length.
5. For the bug's test case, the above condition (REAL_RESULT
Item with max_length = UINT_MAX32) was a result of
Item_func_if::fix_length_and_dec() "shortcutting" aggregation
of argument types when one of the arguments was a constant
NULL. In this case, the attributes of the aggregated type were
simply copied from the other, non-NULL argument, but max_length
was still calculated as per the general, non-shortcut case, by
choosing the greatest of argument's max_length, which is
obviously not correct.
The patch addresses all of the above problems, even though
fixing the assertion failure for the particular test case would
require only a subset of the above problems to be solved.
client/sql_string.cc:
Return an error in case of uint32 overflow in alignment.
Also assert there was no overflow to help find such conditions
in debug builds, since almost no callers check the return value
of String::alloc().
mysql-test/r/func_if.result:
Add a test case for bug #55077.
mysql-test/t/func_if.test:
Add a test case for bug #55077.
sql/field.cc:
- Assert we don't operate with fields wider than 255
(MAX_FIELD_CHARLENGTH) bytes in both Field_float and
Field_double.
- Don't take field_length into account when calculating the
output buffer length.
- Check the return value of String::alloc()
sql/item_cmpfunc.cc:
When shortcutting type aggregation, don't take the NULL
argument's max_length into account.
sql/sql_string.cc:
Return an error in case of uint32 overflow in alignment.
Also assert there was no overflow to help find such conditions
in debug builds, since almost no callers check the return value
of String::alloc().
2010-08-25 17:57:53 +02:00
#
# Bug#55077: Assertion failed: width > 0 && to != ((void *)0), file .\dtoa.c
#
CREATE TABLE t1 (a LONGBLOB, b DOUBLE);
INSERT INTO t1 VALUES (NULL, 0), (NULL, 1);
SELECT IF(b, (SELECT a FROM t1 LIMIT 1), b) c FROM t1 GROUP BY c;
c
NULL
0
DROP TABLE t1;
2011-08-19 09:06:50 +02:00
#
# Bug#12532830
# SIGFPE OR ASSERTION (PRECISION <= ((9 * 9) - 8*2)) && (DEC <= 30)
#
select
sum(distinct(if('a',
(select adddate(elt(convert(9999999999999999999999999999999999999,decimal(64,0)),count(*)),
interval 1 day))
, .1))) as foo;
foo
0.1
Warnings:
Warning 1292 Truncated incorrect DOUBLE value: 'a'
Warning 1292 Truncated incorrect DOUBLE value: 'a'
2012-05-21 20:54:41 +02:00
#
2012-05-17 09:13:25 +02:00
# LP bug#998321 Simple query with IF expression causes an
# assertion abort (see also mysql Bug#12620084)
#
SELECT if(0, (SELECT min('hello')), NULL);
if(0, (SELECT min('hello')), NULL)
NULL
SELECT if(1, (SELECT min('hello')), NULL);
if(1, (SELECT min('hello')), NULL)
hello
SELECT if(0, NULL, (SELECT min('hello')));
if(0, NULL, (SELECT min('hello')))
hello
SELECT if(1, NULL, (SELECT min('hello')));
if(1, NULL, (SELECT min('hello')))
NULL
End of 5.2 tests
2015-09-03 18:00:43 +02:00
#
# MDEV-8663: IF Statement returns multiple values erroneously
# (or Assertion `!null_value' failed in Item::send(Protocol*, String*)
#
CREATE TABLE `t1` (
`datas` VARCHAR(25) NOT NULL
2015-10-12 00:37:58 +02:00
) DEFAULT CHARSET=utf8;
2015-09-03 18:00:43 +02:00
INSERT INTO `t1` VALUES ('1,2'), ('2,3'), ('3,4');
SELECT IF(FIND_IN_SET('1', `datas`), 1.5, IF(FIND_IN_SET('2', `datas`), 2, NULL)) AS `First`, '1' AS `Second`, '2' AS `Third` FROM `t1`;
First Second Third
1.5 1 2
2.0 1 2
NULL 1 2
drop table t1;
