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drop table if exists t1, t2;
select CASE "b" when "a" then 1 when "b" then 2 END;
CASE "b" when "a" then 1 when "b" then 2 END
2
select CASE "c" when "a" then 1 when "b" then 2 END;
CASE "c" when "a" then 1 when "b" then 2 END
NULL
select CASE "c" when "a" then 1 when "b" then 2 ELSE 3 END;
CASE "c" when "a" then 1 when "b" then 2 ELSE 3 END
3
select CASE BINARY "b" when "a" then 1 when "B" then 2 WHEN "b" then "ok" END;
CASE BINARY "b" when "a" then 1 when "B" then 2 WHEN "b" then "ok" END
ok
select CASE "b" when "a" then 1 when binary "B" then 2 WHEN "b" then "ok" END;
CASE "b" when "a" then 1 when binary "B" then 2 WHEN "b" then "ok" END
ok
select CASE concat("a","b") when concat("ab","") then "a" when "b" then "b" end;
CASE concat("a","b") when concat("ab","") then "a" when "b" then "b" end
a
select CASE when 1=0 then "true" else "false" END;
CASE when 1=0 then "true" else "false" END
false
select CASE 1 when 1 then "one" WHEN 2 then "two" ELSE "more" END;
CASE 1 when 1 then "one" WHEN 2 then "two" ELSE "more" END
one
explain extended select CASE 1 when 1 then "one" WHEN 2 then "two" ELSE "more" END;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL NULL No tables used
Warnings:
Note 1003 select (case 1 when 1 then 'one' when 2 then 'two' else 'more' end) AS `CASE 1 when 1 then "one" WHEN 2 then "two" ELSE "more" END`
select CASE 2.0 when 1 then "one" WHEN 2.0 then "two" ELSE "more" END;
CASE 2.0 when 1 then "one" WHEN 2.0 then "two" ELSE "more" END
two
select (CASE "two" when "one" then "1" WHEN "two" then "2" END);
(CASE "two" when "one" then "1" WHEN "two" then "2" END)
2
select (CASE "two" when "one" then 1.00 WHEN "two" then 2.00 END) +0.0;
(CASE "two" when "one" then 1.00 WHEN "two" then 2.00 END) +0.0
2.00
select case 1/0 when "a" then "true" else "false" END;
case 1/0 when "a" then "true" else "false" END
false
Warnings:
Error 1365 Division by 0
select case 1/0 when "a" then "true" END;
case 1/0 when "a" then "true" END
NULL
Warnings:
Error 1365 Division by 0
select (case 1/0 when "a" then "true" END);
(case 1/0 when "a" then "true" END)
NULL
Warnings:
Error 1365 Division by 0
select (case 1/0 when "a" then "true" END) + 0.0;
(case 1/0 when "a" then "true" END) + 0.0
NULL
Warnings:
Error 1365 Division by 0
select case when 1>0 then "TRUE" else "FALSE" END;
case when 1>0 then "TRUE" else "FALSE" END
TRUE
select case when 1<0 then "TRUE" else "FALSE" END;
case when 1<0 then "TRUE" else "FALSE" END
FALSE
create table t1 (a int);
insert into t1 values(1),(2),(3),(4);
select case a when 1 then 2 when 2 then 3 else 0 end as fcase, count(*) from t1 group by fcase;
fcase count(*)
0 2
2 1
3 1
explain extended select case a when 1 then 2 when 2 then 3 else 0 end as fcase, count(*) from t1 group by fcase;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 4 100.00 Using temporary; Using filesort
Warnings:
Note 1003 select (case `test`.`t1`.`a` when 1 then 2 when 2 then 3 else 0 end) AS `fcase`,count(0) AS `count(*)` from `test`.`t1` group by (case `test`.`t1`.`a` when 1 then 2 when 2 then 3 else 0 end)
select case a when 1 then "one" when 2 then "two" else "nothing" end as fcase, count(*) from t1 group by fcase;
fcase count(*)
nothing 2
one 1
two 1
drop table t1;
create table t1 (row int not null, col int not null, val varchar(255) not null);
insert into t1 values (1,1,'orange'),(1,2,'large'),(2,1,'yellow'),(2,2,'medium'),(3,1,'green'),(3,2,'small');
select max(case col when 1 then val else null end) as color from t1 group by row;
color
orange
yellow
green
drop table t1;
CREATE TABLE t1 SELECT
CASE WHEN 1 THEN 'a' COLLATE utf8_bin ELSE 'a' END AS c1,
CASE WHEN 1 THEN 'a' ELSE 'a' COLLATE utf8_bin END AS c2,
CASE WHEN 1 THEN 'a' ELSE 1 END AS c3,
CASE WHEN 1 THEN 1 ELSE 'a' END AS c4,
CASE WHEN 1 THEN 'a' ELSE 1.0 END AS c5,
CASE WHEN 1 THEN 1.0 ELSE 'a' END AS c6,
CASE WHEN 1 THEN 1 ELSE 1.0 END AS c7,
CASE WHEN 1 THEN 1.0 ELSE 1 END AS c8,
CASE WHEN 1 THEN 1.0 END AS c9,
CASE WHEN 1 THEN 0.1e1 else 0.1 END AS c10,
CASE WHEN 1 THEN 0.1e1 else 1 END AS c11,
CASE WHEN 1 THEN 0.1e1 else '1' END AS c12
;
SHOW CREATE TABLE t1;
Table Create Table
t1 CREATE TABLE `t1` (
`c1` VARCHAR(1) COLLATE utf8_bin DEFAULT NULL,
`c2` VARCHAR(1) COLLATE utf8_bin DEFAULT NULL,
`c3` VARBINARY(4) NOT NULL,
`c4` VARBINARY(4) NOT NULL,
`c5` VARBINARY(4) NOT NULL,
`c6` VARBINARY(4) NOT NULL,
`c7` DECIMAL(2,1) NOT NULL,
`c8` DECIMAL(2,1) NOT NULL,
`c9` DECIMAL(2,1) DEFAULT NULL,
`c10` DOUBLE NOT NULL,
`c11` DOUBLE NOT NULL,
`c12` VARBINARY(5) NOT NULL
) ENGINE=DEFAULT COLLATE = utf8_general_ci
DROP TABLE t1;
SELECT CASE
WHEN 1
THEN 'a' COLLATE utf8_bin
ELSE 'a' COLLATE utf8_swedish_ci
END;
ERROR HY000: Illegal mix of collations (utf8_bin,EXPLICIT) and (utf8_swedish_ci,EXPLICIT) for operation 'case'
SELECT CASE 'a' COLLATE utf8_bin
WHEN 'a' COLLATE utf8_danish_ci THEN 1
WHEN 'a' COLLATE utf8_swedish_ci THEN 2
END;
ERROR HY000: Illegal mix of collations (utf8_bin,EXPLICIT), (utf8_danish_ci,EXPLICIT), (utf8_swedish_ci,EXPLICIT) for operation 'case'
SELECT
CASE 'a' COLLATE utf8_general_ci WHEN 'A' THEN '1' ELSE 2 END,
CASE 'a' COLLATE utf8_bin WHEN 'A' THEN '1' ELSE 2 END,
CASE 'a' WHEN 'A' COLLATE utf8_swedish_ci THEN '1' ELSE 2 END,
CASE 'a' WHEN 'A' COLLATE utf8_bin THEN '1' ELSE 2 END
;
CASE 'a' COLLATE utf8_general_ci WHEN 'A' THEN '1' ELSE 2 END CASE 'a' COLLATE utf8_bin WHEN 'A' THEN '1' ELSE 2 END CASE 'a' WHEN 'A' COLLATE utf8_swedish_ci THEN '1' ELSE 2 END CASE 'a' WHEN 'A' COLLATE utf8_bin THEN '1' ELSE 2 END
1 2 1 2
CREATE TABLE t1 SELECT COALESCE('a' COLLATE utf8_swedish_ci,'b' COLLATE utf8_bin);
ERROR HY000: Illegal mix of collations (utf8_swedish_ci,EXPLICIT) and (utf8_bin,EXPLICIT) for operation 'coalesce'
CREATE TABLE t1 SELECT
COALESCE(1), COALESCE(1.0),COALESCE('a'),
COALESCE(1,1.0), COALESCE(1,'1'),COALESCE(1.1,'1'),
COALESCE('a' COLLATE utf8_bin,'b');
explain extended SELECT
COALESCE(1), COALESCE(1.0),COALESCE('a'),
COALESCE(1,1.0), COALESCE(1,'1'),COALESCE(1.1,'1'),
COALESCE('a' COLLATE utf8_bin,'b');
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL NULL No tables used
Warnings:
Note 1003 select coalesce(1) AS `COALESCE(1)`,coalesce(1.0) AS `COALESCE(1.0)`,coalesce('a') AS `COALESCE('a')`,coalesce(1,1.0) AS `COALESCE(1,1.0)`,coalesce(1,'1') AS `COALESCE(1,'1')`,coalesce(1.1,'1') AS `COALESCE(1.1,'1')`,coalesce(('a' collate utf8_bin),'b') AS `COALESCE('a' COLLATE utf8_bin,'b')`
SHOW CREATE TABLE t1;
Table Create Table
t1 CREATE TABLE `t1` (
`COALESCE(1)` INT NOT NULL,
`COALESCE(1.0)` DECIMAL(2,1) NOT NULL,
`COALESCE('a')` VARCHAR(1) COLLATE utf8_general_ci NOT NULL,
`COALESCE(1,1.0)` DECIMAL(2,1) NOT NULL,
`COALESCE(1,'1')` VARBINARY(4) NOT NULL,
`COALESCE(1.1,'1')` VARBINARY(4) NOT NULL,
`COALESCE('a' COLLATE utf8_bin,'b')` VARCHAR(1) COLLATE utf8_bin DEFAULT NULL
) ENGINE=DEFAULT COLLATE = utf8_general_ci
DROP TABLE t1;
SELECT 'case+union+test'
UNION
SELECT CASE LOWER('1') WHEN LOWER('2') THEN 'BUG' ELSE 'nobug' END;
case+union+test
case+union+test
nobug
SELECT CASE LOWER('1') WHEN LOWER('2') THEN 'BUG' ELSE 'nobug' END;
CASE LOWER('1') WHEN LOWER('2') THEN 'BUG' ELSE 'nobug' END
nobug
SELECT 'case+union+test'
UNION
SELECT CASE '1' WHEN '2' THEN 'BUG' ELSE 'nobug' END;
case+union+test
case+union+test
nobug
create table t1(a float, b int default 3);
insert into t1 (a) values (2), (11), (8);
select min(a), min(case when 1=1 then a else NULL end),
min(case when 1!=1 then NULL else a end)
from t1 where b=3 group by b;
min(a) min(case when 1=1 then a else NULL end) min(case when 1!=1 then NULL else a end)
2 2 2
drop table t1;
CREATE TABLE t1 (EMPNUM INT);
INSERT INTO t1 VALUES (0), (2);
CREATE TABLE t2 (EMPNUM DECIMAL (4, 2));
INSERT INTO t2 VALUES (0.0), (9.0);
SELECT COALESCE(t2.EMPNUM,t1.EMPNUM) AS CEMPNUM,
t1.EMPNUM AS EMPMUM1, t2.EMPNUM AS EMPNUM2
FROM t1 LEFT JOIN t2 ON t1.EMPNUM=t2.EMPNUM;
CEMPNUM EMPMUM1 EMPNUM2
0.00 0 0.00
2.00 2 NULL
SELECT IFNULL(t2.EMPNUM,t1.EMPNUM) AS CEMPNUM,
t1.EMPNUM AS EMPMUM1, t2.EMPNUM AS EMPNUM2
FROM t1 LEFT JOIN t2 ON t1.EMPNUM=t2.EMPNUM;
CEMPNUM EMPMUM1 EMPNUM2
0.00 0 0.00
2.00 2 NULL
DROP TABLE t1,t2;
End of 4.1 tests
create table t1 (a int, b bigint);
create table t2 (c int);
insert into t1 (a, b) values (1,4572794622775114594), (2,18196094287899841997),
(3,11120436154190595086);
insert into t2 (c) values (1), (2), (3);
select t1.a, (case t1.a when 0 then 0 else t1.b end) d from t1
join t2 on t1.a=t2.c order by d;
a d
3 -7326307919518956530
2 -250649785809709619
1 4572794622775114594
select t1.a, (case t1.a when 0 then 0 else t1.b end) d from t1
join t2 on t1.a=t2.c where b=11120436154190595086 order by d;
a d
3 -7326307919518956530
drop table t1, t2;
End of 5.0 tests
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