1
drop table if exists t1;
2
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 ;
3
IF(0,"ERROR","this") IF(1,"is","ERROR") IF(NULL,"ERROR","a") IF(1,2,3)|0 IF(1,2.0,3.0)+0
5
CREATE TABLE t1 (st varchar(255) NOT NULL, u int(11) NOT NULL) ENGINE=MyISAM;
6
INSERT INTO t1 VALUES ('a',1),('A',1),('aa',1),('AA',1),('a',1),('aaa',0),('BBB',0);
7
select if(1,st,st) s from t1 order by s;
16
select if(u=1,st,st) s from t1 order by s;
25
select if(u=1,binary st,st) s from t1 order by s;
34
select if(u=1,st,binary st) s from t1 where st like "%a%" order by s;
42
explain extended select if(u=1,st,binary st) s from t1 where st like "%a%" order by s;
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id select_type table type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE t1 ALL NULL NULL NULL NULL 7 100.00 Using where; Using filesort
46
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))
47
select nullif(u, 1) from t1;
56
explain extended select nullif(u, 1) from t1;
57
id select_type table type possible_keys key key_len ref rows filtered Extra
58
1 SIMPLE t1 ALL NULL NULL NULL NULL 7 100.00
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Note 1003 select nullif("test"."t1"."u",1) AS "nullif(u, 1)" from "test"."t1"
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select nullif(1,'test');
66
Warning 1292 Truncated incorrect DOUBLE value: 'test'
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select NULLIF(NULL,NULL), NULLIF(NULL,1), NULLIF(NULL,1.0), NULLIF(NULL,"test");
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NULLIF(NULL,NULL) NULLIF(NULL,1) NULLIF(NULL,1.0) NULLIF(NULL,"test")
70
select NULLIF(1,NULL), NULLIF(1.0, NULL), NULLIF("test", NULL);
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NULLIF(1,NULL) NULLIF(1.0, NULL) NULLIF("test", NULL)
73
create table t1 (num double(12,2));
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insert into t1 values (144.54);
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select sum(if(num is null,0.00,num)) from t1;
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sum(if(num is null,0.00,num))
79
create table t1 (x int, y int);
80
insert into t1 values (0,6),(10,16),(20,26),(30,10),(40,46),(50,56);
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select min(if(y -x > 5,y,NULL)), max(if(y - x > 5,y,NULL)) from t1;
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min(if(y -x > 5,y,NULL)) max(if(y - x > 5,y,NULL))
85
create table t1 (a int);
86
insert t1 values (1),(2);
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select if(1>2,a,avg(a)) from t1;
91
SELECT NULLIF(5,5) IS NULL, NULLIF(5,5) IS NOT NULL;
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NULLIF(5,5) IS NULL NULLIF(5,5) IS NOT NULL
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`id` int(11) NOT NULL ,
96
`date` int(10) default NULL,
97
`text` varchar(32) NOT NULL
99
INSERT INTO t1 VALUES (1,1110000000,'Day 1'),(2,1111000000,'Day 2'),(3,1112000000,'Day 3');
100
SELECT id, IF(date IS NULL, '-', FROM_UNIXTIME(date, '%d-%m-%Y')) AS date_ord, text FROM t1 ORDER BY date_ord ASC;
105
SELECT id, IF(date IS NULL, '-', FROM_UNIXTIME(date, '%d-%m-%Y')) AS date_ord, text FROM t1 ORDER BY date_ord DESC;
111
CREATE TABLE t1 (a CHAR(10));
112
INSERT INTO t1 VALUES ('aaa'), (NULL), (''), ('bbb');
113
SELECT a, NULLIF(a,'') FROM t1;
119
SELECT a, NULLIF(a,'') FROM t1 WHERE NULLIF(a,'') IS NULL;
124
create table t1 (f1 int, f2 int);
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insert into t1 values(1,1),(0,0);
126
select f1, f2, if(f1, 40.0, 5.00) from t1 group by f1 order by f2;
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f1 f2 if(f1, 40.0, 5.00)
131
select if(0, 18446744073709551610, 18446744073709551610);
132
if(0, 18446744073709551610, 18446744073709551610)