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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 ;
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
CREATE TABLE t1 (st varchar(255) NOT NULL, u int(11) NOT NULL) ENGINE=MyISAM;
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;
s
a
A
a
aa
AA
aaa
BBB
select if(u=1,st,st) s from t1 order by s;
s
a
A
a
aa
AA
aaa
BBB
select if(u=1,binary st,st) s from t1 order by s;
s
A
AA
BBB
a
a
aa
aaa
select if(u=1,st,binary st) s from t1 where st like "%a%" order by s;
s
A
AA
a
a
aa
aaa
explain extended select if(u=1,st,binary st) s from t1 where st like "%a%" order by s;
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
Warnings:
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))
select nullif(u, 1) from t1;
nullif(u, 1)
NULL
NULL
NULL
NULL
NULL
0
0
explain extended select nullif(u, 1) from t1;
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
Warnings:
Note 1003 select nullif(`test`.`t1`.`u`,1) AS `nullif(u, 1)` from `test`.`t1`
drop table t1;
select nullif(1,'test');
nullif(1,'test')
1
Warnings:
Warning 1292 Truncated incorrect DOUBLE value: 'test'
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
create table t1 (num double(12,2));
insert into t1 values (144.54);
select sum(if(num is null,0.00,num)) from t1;
sum(if(num is null,0.00,num))
144.54
drop table t1;
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;
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;
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
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;
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;
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;
select if(0, 18446744073709551610, 18446744073709551610);
if(0, 18446744073709551610, 18446744073709551610)
18446744073709551610
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;
CREATE TABLE t1 (c LONGTEXT);
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
SELECT * FROM (SELECT MAX(IF(1, CAST(c AS UNSIGNED), 0)) FROM t1) AS te;
MAX(IF(1, CAST(c AS UNSIGNED), 0))
1234567890123456789
SELECT * FROM (SELECT MAX(IFNULL(CAST(c AS UNSIGNED), 0)) FROM t1) AS te;
MAX(IFNULL(CAST(c AS UNSIGNED), 0))
1234567890123456789
DROP TABLE t1;
End of 5.0 tests
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