# Testing of CASE # --disable_warnings drop table if exists t1, t2; --enable_warnings SET sql_mode = 'NO_ENGINE_SUBSTITUTION'; select CASE "b" when "a" then 1 when "b" then 2 END; select CASE "c" when "a" then 1 when "b" then 2 END; select CASE "c" when "a" then 1 when "b" then 2 ELSE 3 END; select CASE BINARY "b" when "a" then 1 when "B" then 2 WHEN "b" then "ok" END; select CASE "b" when "a" then 1 when binary "B" then 2 WHEN "b" then "ok" END; select CASE concat("a","b") when concat("ab","") then "a" when "b" then "b" end; select CASE when 1=0 then "true" else "false" END; select CASE 1 when 1 then "one" WHEN 2 then "two" ELSE "more" END; explain select 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; select (CASE "two" when "one" then "1" WHEN "two" then "2" END) | 0; select (CASE "two" when "one" then 1.00 WHEN "two" then 2.00 END) +0.0; select case 1/0 when "a" then "true" else "false" END; select case 1/0 when "a" then "true" END; select (case 1/0 when "a" then "true" END) | 0; select (case 1/0 when "a" then "true" END) + 0.0; select case when 1>0 then "TRUE" else "FALSE" END; select case when 1<0 then "TRUE" else "FALSE" END; # # Test bug when using GROUP BY on CASE # 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; analyze table t1; explain select case a when 1 then 2 when 2 then 3 else 0 end as fcase, count(*) from t1 group by fcase; select case a when 1 then "one" when 2 then "two" else "nothing" end as fcase, count(*) from t1 group by fcase; drop table t1; # # Test MAX(CASE ... ) that can return null # 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`; drop table t1; SET NAMES latin1; # # CASE and argument types/collations aggregation into result # CREATE TABLE t1 SELECT CASE WHEN 1 THEN _latin1'a' COLLATE latin1_danish_ci ELSE _latin1'a' END AS c1, CASE WHEN 1 THEN _latin1'a' ELSE _latin1'a' COLLATE latin1_danish_ci 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; DROP TABLE t1; --error 1267 SELECT CASE WHEN 1 THEN _latin1'a' COLLATE latin1_danish_ci ELSE _latin1'a' COLLATE latin1_swedish_ci END; --error 1270 SELECT CASE _latin1'a' COLLATE latin1_general_ci WHEN _latin1'a' COLLATE latin1_danish_ci THEN 1 WHEN _latin1'a' COLLATE latin1_swedish_ci THEN 2 END; SELECT CASE _latin1'a' COLLATE latin1_general_ci WHEN _latin1'A' THEN '1' ELSE 2 END, CASE _latin1'a' COLLATE latin1_bin WHEN _latin1'A' THEN '1' ELSE 2 END, CASE _latin1'a' WHEN _latin1'A' COLLATE latin1_swedish_ci THEN '1' ELSE 2 END, CASE _latin1'a' WHEN _latin1'A' COLLATE latin1_bin THEN '1' ELSE 2 END ; # # COALESCE is a CASE abbrevation: # # COALESCE(v1,v2) == CASE WHEN v1 IS NOT NULL THEN v1 ELSE v2 END # # COALESCE(V1, V2, . . . ,Vn ) = # CASE WHEN V1 IS NOT NULL THEN V1 ELSE COALESCE (V2, . . . ,Vn) END # # Check COALESCE argument types aggregation --error 1267 CREATE TABLE t1 SELECT COALESCE(_latin1'a',_latin2'a'); --error 1267 CREATE TABLE t1 SELECT COALESCE('a' COLLATE latin1_swedish_ci,'b' COLLATE latin1_bin); 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 latin1_bin,'b'); explain SELECT COALESCE(1), COALESCE(1.0),COALESCE('a'), COALESCE(1,1.0), COALESCE(1,'1'),COALESCE(1.1,'1'), COALESCE('a' COLLATE latin1_bin,'b'); SHOW CREATE TABLE t1; DROP TABLE t1; --error 1267 CREATE TABLE t1 SELECT IFNULL('a' COLLATE latin1_swedish_ci, 'b' COLLATE latin1_bin); # Test for BUG#10151 SELECT 'case+union+test' UNION SELECT CASE LOWER('1') WHEN LOWER('2') THEN 'BUG' ELSE 'nobug' END; SELECT CASE LOWER('1') WHEN LOWER('2') THEN 'BUG' ELSE 'nobug' END; SELECT 'case+union+test' UNION SELECT CASE '1' WHEN '2' THEN 'BUG' ELSE 'nobug' END; # # Bug #17896: problem with MIN(CASE...) # 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; drop table t1; # # Tests for bug #9939: conversion of the arguments for COALESCE and IFNULL # 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; 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; DROP TABLE t1,t2; --echo End of 4.1 tests # # #30782: Truncated UNSIGNED BIGINT columns # create table t1 (a int, b bigint unsigned); 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; 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; drop table t1, t2; --echo End of 5.0 tests # # Bug #11764313 57135: CRASH IN ITEM_FUNC_CASE::FIND_ITEM WITH CASE WHEN # ELSE CLAUSE # CREATE TABLE t1(a YEAR); SELECT 1 FROM t1 WHERE a=1 AND CASE 1 WHEN a THEN 1 ELSE 1 END; DROP TABLE t1; SET sql_mode = default; --echo # --echo # Bug#19875294 ASSERTION `SRC' FAILED IN MY_STRNXFRM_UNICODE --echo # (SIG 6 -STRINGS/CTYPE-UTF8.C:5151) --echo # set @@sql_mode=''; CREATE TABLE t1(c1 SET('','')CHARACTER SET ucs2) engine=innodb; INSERT INTO t1 VALUES(990101.102); SELECT COALESCE(c1)FROM t1 ORDER BY 1; DROP TABLE t1; set @@sql_mode=default; --echo # Bug#24733658: IF and friends give wrong type for signed and unsigned CREATE TABLE source(bt INTEGER, bf INTEGER, i8u BIGINT UNSIGNED, i8s BIGINT); INSERT INTO source VALUES (1,0,0,-9223372036854775808), (1,0,18446744073709551615,9223372036854775807); CREATE TABLE target SELECT IF(bt,i8u,i8s) AS u, IF(bf,i8u,i8s) AS s FROM source; SHOW CREATE TABLE target; SELECT IF(bt,i8u,i8s) AS u, IF(bf,i8u,i8s) AS s FROM source; SELECT * FROM target; DROP TABLE target; CREATE TABLE target SELECT CASE WHEN bt THEN i8u ELSE i8s END AS u, CASE WHEN bf THEN i8u ELSE i8s END AS s FROM source; SHOW CREATE TABLE target; SELECT CASE WHEN bt THEN i8u ELSE i8s END AS u, CASE WHEN bf THEN i8u ELSE i8s END AS s FROM source; SELECT * FROM target; DROP TABLE target; CREATE TABLE target SELECT CASE bt WHEN TRUE THEN i8u WHEN FALSE THEN i8s END AS u, CASE bf WHEN TRUE THEN i8u WHEN FALSE THEN i8s END AS s FROM source; SHOW CREATE TABLE target; SELECT CASE bt WHEN TRUE THEN i8u WHEN FALSE THEN i8s END AS u, CASE bf WHEN TRUE THEN i8u WHEN FALSE THEN i8s END AS s FROM source; SELECT * FROM target; DROP TABLE target; CREATE TABLE target SELECT COALESCE(i8u, i8s) AS u, COALESCE(i8s, i8u) AS s FROM source; SHOW CREATE TABLE target; SELECT COALESCE(i8u, i8s) AS u, COALESCE(i8s, i8u) AS s FROM source; SELECT * FROM target; DROP TABLE source, target; --echo # Bug#25139420: BIT(n) data type confused when used with IF, IFNULL CREATE TABLE t (a bit(5)); INSERT INTO t VALUES (0),(1),(2),(3),(4),(5),(6),(7),(8),(9), (10),(11),(12),(19),(20),(21),(29),(30),(31); let $query= SELECT HEX(a), IFNULL(a,a) AS b, IFNULL(a,a)+0 AS c, IFNULL(a+0,a+0) AS d, IFNULL(a+0,a) AS e, IFNULL(a,a+0) AS f FROM t; eval $query; eval CREATE TABLE u AS $query; SHOW CREATE TABLE u; DROP TABLE t, u; --echo # Bug#26389402: Outer join optimized away with user-defined functions CREATE TABLE t00(a INTEGER); INSERT INTO t00 VALUES (1),(2); CREATE TABLE t01(a INTEGER); INSERT INTO t01 VALUES (1); CREATE VIEW v0 AS SELECT t00.a, t01.a AS b, IFNULL(t01.a, 666) AS c FROM t00 LEFT JOIN t01 USING(a); SELECT * FROM v0 WHERE c >= 0; CREATE FUNCTION f(a INTEGER) RETURNS INTEGER DETERMINISTIC RETURN IFNULL(a, 666); CREATE VIEW v1 AS SELECT t00.a, t01.a AS b, f(t01.a) AS c FROM t00 LEFT JOIN t01 USING(a); SELECT * FROM v1 WHERE c >= 0; CREATE VIEW v2 AS SELECT t00.a, t01.a AS b, f(IFNULL(t01.a, NULL)) AS c FROM t00 LEFT JOIN t01 USING(a); SELECT * FROM v2 WHERE c >= 0; SELECT t00.a, t01.a AS b, f(t01.a) AS c FROM t00 LEFT JOIN t01 USING(a) WHERE f(t01.a) >= 0; DROP FUNCTION f; DROP VIEW v0, v1, v2; DROP TABLE t00, t01; --echo # --echo # Bug #25051195 Wrong calculation of decimals after point for IFNULL w/ GROUP BY using --echo # temporary table. CREATE TABLE t (i1 INT, d1 DOUBLE, e2 DECIMAL(5,2)); INSERT INTO t VALUES ( 6, 6.0, 10.0/3), ( null, 9.0, 10.0/3), ( 1, null, 10.0/3), ( 2, 2.0, null ); --echo IFNULL and IF should yield same number for decimals after point here SELECT IFNULL(e2,i1) nullif_c, IF(e2 IS NULL,i1,e2) if_c, SUM(d1) FROM t GROUP BY e2,i1 ORDER BY nullif_c, SUM(d1); DROP TABLE t; --echo # Bug#29463760 In cases like ifnull(datetime(2), time(3), wrong answer # Establish a specific date for use when extending TIME values: SET TIMESTAMP=UNIX_TIMESTAMP('2019-03-11 12:00:00'); CREATE TABLE t1 (dt2 DATETIME(2), t3 TIME(3), d DATE); INSERT INTO t1 VALUES ('2001-01-01 00:00:00.12', '00:00:00.567', '2002-01-01'); SELECT CONCAT(IFNULL(t3, d)) AS col1 FROM t1; SELECT CONCAT(IFNULL(t3, d)) AS col1 FROM t1 GROUP BY col1; SET TIMESTAMP=DEFAULT; DROP TABLE t1;