# Initialise --disable_warnings drop table if exists t1, t2; --enable_warnings # # test of IN (NULL) # select 1 in (1,2,3); select 10 in (1,2,3); select NULL in (1,2,3); select 1 in (1,NULL,3); select 3 in (1,NULL,3); select 10 in (1,NULL,3); select 1.5 in (1.5,2.5,3.5); select 10.5 in (1.5,2.5,3.5); select NULL in (1.5,2.5,3.5); select 1.5 in (1.5,NULL,3.5); select 3.5 in (1.5,NULL,3.5); select 10.5 in (1.5,NULL,3.5); CREATE TABLE t1 (a int, b int, c int); insert into t1 values (1,2,3), (1,NULL,3); select 1 in (a,b,c) from t1; select 3 in (a,b,c) from t1; select 10 in (a,b,c) from t1; select NULL in (a,b,c) from t1; drop table t1; CREATE TABLE t1 (a float, b float, c float); insert into t1 values (1.5,2.5,3.5), (1.5,NULL,3.5); select 1.5 in (a,b,c) from t1; select 3.5 in (a,b,c) from t1; select 10.5 in (a,b,c) from t1; drop table t1; CREATE TABLE t1 (a varchar(10), b varchar(10), c varchar(10)); insert into t1 values ('A','BC','EFD'), ('A',NULL,'EFD'); select 'A' in (a,b,c) from t1; select 'EFD' in (a,b,c) from t1; select 'XSFGGHF' in (a,b,c) from t1; drop table t1; CREATE TABLE t1 (field char(1)); INSERT INTO t1 VALUES ('A'),(NULL); SELECT * from t1 WHERE field IN (NULL); SELECT * from t1 WHERE field NOT IN (NULL); SELECT * from t1 where field = field; SELECT * from t1 where field <=> field; DELETE FROM t1 WHERE field NOT IN (NULL); SELECT * FROM t1; drop table t1; create table t1 (id int(10) primary key); insert into t1 values (1),(2),(3),(4),(5),(6),(7),(8),(9); select * from t1 where id in (2,5,9); drop table t1; create table t1 ( a char(1) character set latin1 collate latin1_general_ci, b char(1) character set latin1 collate latin1_swedish_ci, c char(1) character set latin1 collate latin1_danish_ci ); insert into t1 values ('A','B','C'); insert into t1 values ('a','c','c'); --error 1267 select * from t1 where a in (b); --error 1270 select * from t1 where a in (b,c); --error 1271 select * from t1 where 'a' in (a,b,c); select * from t1 where 'a' in (a); select * from t1 where a in ('a'); select * from t1 where 'a' collate latin1_general_ci in (a,b,c); select * from t1 where 'a' collate latin1_bin in (a,b,c); select * from t1 where 'a' in (a,b,c collate latin1_bin); explain extended select * from t1 where 'a' in (a,b,c collate latin1_bin); drop table t1; set names utf8; create table t1 (a char(10) character set utf8 not null); insert into t1 values ('bbbb'),(_koi8r'ÃÃÃÃ'),(_latin1'ÄÄÄÄ'); select a from t1 where a in ('bbbb',_koi8r'ÃÃÃÃ',_latin1'ÄÄÄÄ') order by a; drop table t1; # Bug#7834 Illegal mix of collations in IN operator create table t1 (a char(10) character set latin1 not null); insert into t1 values ('a'),('b'),('c'); select a from t1 where a IN ('a','b','c') order by a; drop table t1; set names latin1; select '1.0' in (1,2); select 1 in ('1.0',2); select 1 in (1,'2.0'); select 1 in ('1.0',2.0); select 1 in (1.0,'2.0'); select 1 in ('1.1',2); select 1 in ('1.1',2.0); # Test case for bug #6365 create table t1 (a char(2) character set binary); insert into t1 values ('aa'), ('bb'); select * from t1 where a in (NULL, 'aa'); drop table t1; # BUG#13419 create table t1 (id int, key(id)); insert into t1 values (1),(2),(3); select count(*) from t1 where id not in (1); select count(*) from t1 where id not in (1,2); drop table t1; # # BUG#17047: CHAR() and IN() can return NULL without signaling NULL # result # # The problem was in the IN() function that ignored maybe_null flags # of all arguments except the first (the one _before_ the IN # keyword, '1' in the test case below). # --disable_warnings DROP TABLE IF EXISTS t1; --enable_warnings CREATE TABLE t1 SELECT 1 IN (2, NULL); --echo SELECT should return NULL. SELECT * FROM t1; DROP TABLE t1; --echo End of 4.1 tests # # Bug #11885: WHERE condition with NOT IN (one element) # CREATE TABLE t1 (a int PRIMARY KEY); INSERT INTO t1 VALUES (44), (45), (46); SELECT * FROM t1 WHERE a IN (45); SELECT * FROM t1 WHERE a NOT IN (0, 45); SELECT * FROM t1 WHERE a NOT IN (45); CREATE VIEW v1 AS SELECT * FROM t1 WHERE a NOT IN (45); SHOW CREATE VIEW v1; SELECT * FROM v1; DROP VIEW v1; DROP TABLE t1; # BUG#15872: Excessive memory consumption of range analysis of NOT IN create table t1 (a int); insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); create table t2 (a int, filler char(200), key(a)); insert into t2 select C.a*2, 'no' from t1 A, t1 B, t1 C; insert into t2 select C.a*2+1, 'yes' from t1 C; explain select * from t2 where a NOT IN (0, 2,4,6,8,10,12,14,16,18); select * from t2 where a NOT IN (0, 2,4,6,8,10,12,14,16,18); explain select * from t2 force index(a) where a NOT IN (2,2,2,2,2,2); explain select * from t2 force index(a) where a <> 2; drop table t2; # # Repeat the test for DATETIME # create table t2 (a datetime, filler char(200), key(a)); insert into t2 select '2006-04-25 10:00:00' + interval C.a minute, 'no' from t1 A, t1 B, t1 C where C.a % 2 = 0; insert into t2 select '2006-04-25 10:00:00' + interval C.a*2+1 minute, 'yes' from t1 C; explain select * from t2 where a NOT IN ( '2006-04-25 10:00:00','2006-04-25 10:02:00','2006-04-25 10:04:00', '2006-04-25 10:06:00', '2006-04-25 10:08:00'); select * from t2 where a NOT IN ( '2006-04-25 10:00:00','2006-04-25 10:02:00','2006-04-25 10:04:00', '2006-04-25 10:06:00', '2006-04-25 10:08:00'); drop table t2; # # Repeat the test for CHAR(N) # create table t2 (a varchar(10), filler char(200), key(a)); insert into t2 select 'foo', 'no' from t1 A, t1 B; insert into t2 select 'barbar', 'no' from t1 A, t1 B; insert into t2 select 'bazbazbaz', 'no' from t1 A, t1 B; insert into t2 values ('fon', '1'), ('fop','1'), ('barbaq','1'), ('barbas','1'), ('bazbazbay', '1'),('zz','1'); explain select * from t2 where a not in('foo','barbar', 'bazbazbaz'); drop table t2; # # Repeat for DECIMAL # create table t2 (a decimal(10,5), filler char(200), key(a)); insert into t2 select 345.67890, 'no' from t1 A, t1 B; insert into t2 select 43245.34, 'no' from t1 A, t1 B; insert into t2 select 64224.56344, 'no' from t1 A, t1 B; insert into t2 values (0, '1'), (22334.123,'1'), (33333,'1'), (55555,'1'), (77777, '1'); explain select * from t2 where a not in (345.67890, 43245.34, 64224.56344); select * from t2 where a not in (345.67890, 43245.34, 64224.56344); drop table t2; # Try a very big IN-list create table t2 (a int, key(a), b int); insert into t2 values (1,1),(2,2); set @cnt= 1; set @str="update t2 set b=1 where a not in ("; select count(*) from ( select @str:=concat(@str, @cnt:=@cnt+1, ",") from t1 A, t1 B, t1 C, t1 D) Z; set @str:=concat(@str, "10000)"); select substr(@str, 1, 50); prepare s from @str; execute s; deallocate prepare s; set @str=NULL; drop table t2; drop table t1; # BUG#19618: Crash in range optimizer for # "unsigned_keypart NOT IN(negative_number,...)" # (introduced in fix BUG#15872) create table t1 ( some_id smallint(5) unsigned, key (some_id) ); insert into t1 values (1),(2); select some_id from t1 where some_id not in(2,-1); select some_id from t1 where some_id not in(-4,-1,-4); select some_id from t1 where some_id not in(-4,-1,3423534,2342342); # # BUG#24261: crash when WHERE contains NOT IN ('') for unsigned column type # select some_id from t1 where some_id not in('-1', '0'); drop table t1; # # BUG#20420: optimizer reports wrong keys on left join with IN # CREATE TABLE t1 (a int, b int, PRIMARY KEY (a)); INSERT INTO t1 VALUES (1,1),(2,1),(3,1),(4,1),(5,1),(6,1); CREATE TABLE t2 (a int, b int, PRIMARY KEY (a)); INSERT INTO t2 VALUES (3,2),(4,2),(100,100),(101,201),(102,102); CREATE TABLE t3 (a int PRIMARY KEY); INSERT INTO t3 VALUES (1),(2),(3),(4); CREATE TABLE t4 (a int PRIMARY KEY,b int); INSERT INTO t4 VALUES (1,1),(2,2),(1000,1000),(1001,1001),(1002,1002), (1003,1003),(1004,1004); EXPLAIN SELECT STRAIGHT_JOIN * FROM t3 JOIN t1 ON t3.a=t1.a JOIN t2 ON t3.a=t2.a JOIN t4 WHERE t4.a IN (t1.b, t2.b); SELECT STRAIGHT_JOIN * FROM t3 JOIN t1 ON t3.a=t1.a JOIN t2 ON t3.a=t2.a JOIN t4 WHERE t4.a IN (t1.b, t2.b); EXPLAIN SELECT STRAIGHT_JOIN (SELECT SUM(t4.a) FROM t4 WHERE t4.a IN (t1.b, t2.b)) FROM t3, t1, t2 WHERE t3.a=t1.a AND t3.a=t2.a; SELECT STRAIGHT_JOIN (SELECT SUM(t4.a) FROM t4 WHERE t4.a IN (t1.b, t2.b)) FROM t3, t1, t2 WHERE t3.a=t1.a AND t3.a=t2.a; DROP TABLE t1,t2,t3,t4; # # BUG#19342: IN works incorrectly for BIGINT UNSIGNED values # CREATE TABLE t1(a BIGINT UNSIGNED); INSERT INTO t1 VALUES (0xFFFFFFFFFFFFFFFF); SELECT * FROM t1 WHERE a=-1 OR a=-2 ; SELECT * FROM t1 WHERE a IN (-1, -2); CREATE TABLE t2 (a BIGINT UNSIGNED); insert into t2 values(13491727406643098568), (0x7fffffefffffffff), (0x7ffffffeffffffff), (0x7fffffffefffffff), (0x7ffffffffeffffff), (0x7fffffffffefffff), (0x7ffffffffffeffff), (0x7fffffffffffefff), (0x7ffffffffffffeff), (0x7fffffffffffffef), (0x7ffffffffffffffe), (0x7fffffffffffffff), (0x8000000000000000), (0x8000000000000001), (0x8000000000000002), (0x8000000000000300), (0x8000000000000400), (0x8000000000000401), (0x8000000000004001), (0x8000000000040001), (0x8000000000400001), (0x8000000004000001), (0x8000000040000001), (0x8000000400000001), (0x8000004000000001), (0x8000040000000001); SELECT HEX(a) FROM t2 WHERE a IN (CAST(0xBB3C3E98175D33C8 AS UNSIGNED), 42); SELECT HEX(a) FROM t2 WHERE a IN (CAST(0xBB3C3E98175D33C8 AS UNSIGNED), CAST(0x7fffffffffffffff AS UNSIGNED), CAST(0x8000000000000000 AS UNSIGNED), CAST(0x8000000000000400 AS UNSIGNED), CAST(0x8000000000000401 AS UNSIGNED), 42); SELECT HEX(a) FROM t2 WHERE a IN (CAST(0x7fffffffffffffff AS UNSIGNED), CAST(0x8000000000000001 AS UNSIGNED)); SELECT HEX(a) FROM t2 WHERE a IN (CAST(0x7ffffffffffffffe AS UNSIGNED), CAST(0x7fffffffffffffff AS UNSIGNED)); SELECT HEX(a) FROM t2 WHERE a IN (0x7ffffffffffffffe, 0x7fffffffffffffff, 'abc'); CREATE TABLE t3 (a BIGINT UNSIGNED); INSERT INTO t3 VALUES (9223372036854775551); SELECT HEX(a) FROM t3 WHERE a IN (9223372036854775807, 42); CREATE TABLE t4 (a DATE); INSERT INTO t4 VALUES ('1972-02-06'), ('1972-07-29'); SELECT * FROM t4 WHERE a IN ('1972-02-06','19772-07-29'); DROP TABLE t1,t2,t3,t4; # # BUG#27362: IN with a decimal expression that may return NULL # CREATE TABLE t1 (id int not null); INSERT INTO t1 VALUES (1),(2); SELECT id FROM t1 WHERE id IN(4564, (SELECT IF(1=0,1,1/0)) ); DROP TABLE t1; --echo End of 5.0 tests # # Bug#18360: Type aggregation for IN and CASE may lead to a wrong result # create table t1(f1 char(1)); insert into t1 values ('a'),('b'),('1'); select f1 from t1 where f1 in ('a',1); select f1, case f1 when 'a' then '+' when 1 then '-' end from t1; create index t1f1_idx on t1(f1); select f1 from t1 where f1 in ('a',1); explain select f1 from t1 where f1 in ('a',1); select f1 from t1 where f1 in ('a','b'); explain select f1 from t1 where f1 in ('a','b'); select f1 from t1 where f1 in (2,1); explain select f1 from t1 where f1 in (2,1); create table t2(f2 int, index t2f2(f2)); insert into t2 values(0),(1),(2); select f2 from t2 where f2 in ('a',2); explain select f2 from t2 where f2 in ('a',2); select f2 from t2 where f2 in ('a','b'); explain select f2 from t2 where f2 in ('a','b'); select f2 from t2 where f2 in (1,'b'); explain select f2 from t2 where f2 in (1,'b'); drop table t1, t2; # # Bug #31075: crash in get_func_mm_tree # create table t1 (a time, key(a)); insert into t1 values (),(),(),(),(),(),(),(),(),(); select a from t1 where a not in (a,a,a) group by a; drop table t1; # # Bug #37761: IN handles NULL differently for table-subquery and value-list # create table t1 (id int); select * from t1 where NOT id in (select null union all select 1); select * from t1 where NOT id in (null, 1); drop table t1; # # Bug #41363: crash of mysqld on windows with aggregate in case # CREATE TABLE t1(c0 INTEGER, c1 INTEGER, c2 INTEGER); INSERT INTO t1 VALUES(1, 1, 1), (1, 1, 1); SELECT CASE AVG (c0) WHEN c1 * c2 THEN 1 END FROM t1; SELECT CASE c1 * c2 WHEN SUM(c0) THEN 1 WHEN AVG(c0) THEN 2 END FROM t1; SELECT CASE c1 WHEN c1 + 1 THEN 1 END, ABS(AVG(c0)) FROM t1; DROP TABLE t1; # # Bug #44399: crash with statement using TEXT columns, aggregates, GROUP BY, # and HAVING # CREATE TABLE t1(a TEXT, b INT, c INT UNSIGNED, d DECIMAL(12,2), e REAL); INSERT INTO t1 VALUES('iynfj', 1, 1, 1, 1); INSERT INTO t1 VALUES('innfj', 2, 2, 2, 2); SELECT SUM( DISTINCT a ) FROM t1 GROUP BY a HAVING a IN ( AVG( 1 ), 1 + a); SELECT SUM( DISTINCT b ) FROM t1 GROUP BY b HAVING b IN ( AVG( 1 ), 1 + b); SELECT SUM( DISTINCT c ) FROM t1 GROUP BY c HAVING c IN ( AVG( 1 ), 1 + c); SELECT SUM( DISTINCT d ) FROM t1 GROUP BY d HAVING d IN ( AVG( 1 ), 1 + d); SELECT SUM( DISTINCT e ) FROM t1 GROUP BY e HAVING e IN ( AVG( 1 ), 1 + e); SELECT SUM( DISTINCT e ) FROM t1 GROUP BY b,c,d HAVING (b,c,d) IN ((AVG( 1 ), 1 + c, 1 + d), (AVG( 1 ), 2 + c, 2 + d)); DROP TABLE t1; --echo # --echo # Bug #44139: Table scan when NULL appears in IN clause --echo # --disable_warnings CREATE TABLE t1 ( c_int INT NOT NULL, c_decimal DECIMAL(5,2) NOT NULL, c_float FLOAT(5, 2) NOT NULL, c_bit BIT(10) NOT NULL, c_date DATE NOT NULL, c_datetime DATETIME NOT NULL, c_timestamp TIMESTAMP NOT NULL, c_time TIME NOT NULL, c_year YEAR NOT NULL, c_char CHAR(10) NOT NULL, INDEX(c_int), INDEX(c_decimal), INDEX(c_float), INDEX(c_bit), INDEX(c_date), INDEX(c_datetime), INDEX(c_timestamp), INDEX(c_time), INDEX(c_year), INDEX(c_char)); INSERT IGNORE INTO t1 (c_int) VALUES (1), (2), (3), (4), (5); INSERT IGNORE INTO t1 (c_int) SELECT 0 FROM t1; INSERT IGNORE INTO t1 (c_int) SELECT 0 FROM t1; --enable_warnings EXPLAIN SELECT * FROM t1 WHERE c_int IN (1, 2, 3); EXPLAIN SELECT * FROM t1 WHERE c_int IN (NULL, 1, 2, 3); EXPLAIN SELECT * FROM t1 WHERE c_int IN (1, 2, 3); EXPLAIN SELECT * FROM t1 WHERE c_int IN (1, NULL, 2, NULL, 3, NULL); EXPLAIN SELECT * FROM t1 WHERE c_int IN (NULL); EXPLAIN SELECT * FROM t1 WHERE c_int IN (NULL, NULL); EXPLAIN SELECT * FROM t1 WHERE c_decimal IN (1, 2, 3); EXPLAIN SELECT * FROM t1 WHERE c_decimal IN (NULL, 1, 2, 3); EXPLAIN SELECT * FROM t1 WHERE c_decimal IN (NULL); EXPLAIN SELECT * FROM t1 WHERE c_decimal IN (NULL, NULL); EXPLAIN SELECT * FROM t1 WHERE c_float IN (1, 2, 3); EXPLAIN SELECT * FROM t1 WHERE c_float IN (NULL, 1, 2, 3); EXPLAIN SELECT * FROM t1 WHERE c_float IN (NULL); EXPLAIN SELECT * FROM t1 WHERE c_float IN (NULL, NULL); EXPLAIN SELECT * FROM t1 WHERE c_bit IN (1, 2, 3); EXPLAIN SELECT * FROM t1 WHERE c_bit IN (NULL, 1, 2, 3); EXPLAIN SELECT * FROM t1 WHERE c_bit IN (NULL); EXPLAIN SELECT * FROM t1 WHERE c_bit IN (NULL, NULL); EXPLAIN SELECT * FROM t1 WHERE c_date IN ('2009-09-01', '2009-09-02', '2009-09-03'); EXPLAIN SELECT * FROM t1 WHERE c_date IN (NULL, '2009-09-01', '2009-09-02', '2009-09-03'); EXPLAIN SELECT * FROM t1 WHERE c_date IN (NULL); EXPLAIN SELECT * FROM t1 WHERE c_date IN (NULL, NULL); EXPLAIN SELECT * FROM t1 WHERE c_datetime IN ('2009-09-01 00:00:01', '2009-09-02 00:00:01', '2009-09-03 00:00:01'); EXPLAIN SELECT * FROM t1 WHERE c_datetime IN (NULL, '2009-09-01 00:00:01', '2009-09-02 00:00:01', '2009-09-03 00:00:01'); EXPLAIN SELECT * FROM t1 WHERE c_datetime IN (NULL); EXPLAIN SELECT * FROM t1 WHERE c_datetime IN (NULL, NULL); EXPLAIN SELECT * FROM t1 WHERE c_timestamp IN ('2009-09-01 00:00:01', '2009-09-01 00:00:02', '2009-09-01 00:00:03'); EXPLAIN SELECT * FROM t1 WHERE c_timestamp IN (NULL, '2009-09-01 00:00:01', '2009-09-01 00:00:02', '2009-09-01 00:00:03'); EXPLAIN SELECT * FROM t1 WHERE c_timestamp IN (NULL); EXPLAIN SELECT * FROM t1 WHERE c_timestamp IN (NULL, NULL); EXPLAIN SELECT * FROM t1 WHERE c_year IN (1, 2, 3); EXPLAIN SELECT * FROM t1 WHERE c_year IN (NULL, 1, 2, 3); EXPLAIN SELECT * FROM t1 WHERE c_year IN (NULL); EXPLAIN SELECT * FROM t1 WHERE c_year IN (NULL, NULL); EXPLAIN SELECT * FROM t1 WHERE c_char IN ('1', '2', '3'); EXPLAIN SELECT * FROM t1 WHERE c_char IN (NULL, '1', '2', '3'); EXPLAIN SELECT * FROM t1 WHERE c_char IN (NULL); EXPLAIN SELECT * FROM t1 WHERE c_char IN (NULL, NULL); DROP TABLE t1; --echo # --echo # Bug#54477: Crash on IN / CASE with NULL arguments --echo # CREATE TABLE t1 (a INT); INSERT INTO t1 VALUES (1), (2); SELECT 1 IN (NULL, a) FROM t1; SELECT a IN (a, a) FROM t1 GROUP BY a WITH ROLLUP; SELECT CASE a WHEN a THEN a END FROM t1 GROUP BY a WITH ROLLUP; DROP TABLE t1; --echo # --echo # Bug #11766212 59270: NOT IN (YEAR( ... ), ... ) PRODUCES MANY VALGRIND WARNINGS --echo # SELECT 1 IN (YEAR(FROM_UNIXTIME(NULL)) ,1); --echo # --echo # --echo # Bug#13012483: EXPLAIN EXTENDED, PREPARED STATEMENT, CRASH IN CHECK_SIMPLE_EQUALITY --echo # CREATE TABLE t1 (a INT); PREPARE s FROM "SELECT 1 FROM t1 WHERE 1 < ALL (SELECT @:= (1 IN (SELECT 1 FROM t1)) FROM t1)"; EXECUTE s; DROP TABLE t1; --echo # End of test BUG#13012483 --echo # --echo End of 5.1 tests # # lp:817966 int_column IN (string_constant) # # rather illogically, when BIGINT field is compared to a string, # the string is converted to an integer, not to a double. # When some other integer field (not BIGINT) is compared to a string, # or when the BIGINT is not a field, but an expression, both # operands are compared as doubles. The latter behavior is correct, # according to the manual. # create table t1 (a bigint, b int); insert t1 values (1,1),(2,2),(3,3); select * from t1 where a in ('2.1'); select * from t1 where b in ('2.1'); select * from t1 where a='2.1'; select * from t1 where b='2.1'; select * from t1 where IF(1,a,a)='2.1'; drop table t1; --echo # --echo # LP bug#992380 Crash when creating PS for a query with --echo # subquery in WHERE (see also mysql bug#13012483) --echo # CREATE TABLE t1 (a INT); PREPARE s FROM "SELECT 1 FROM t1 WHERE 1 < ALL (SELECT @:= (1 IN (SELECT 1 FROM t1)) FROM t1)"; EXECUTE s; DROP TABLE t1; --echo # --echo # End of 5.3 tests --echo # # # Bug#26361149 MYSQL SERVER CRASHES AT: COL IN(IFNULL(CONST, COL), NAME_CONST('NAME', NULL)) # create table t1 (a int); insert t1 values (1),(2),(3); select * from t1 where 1 in (a, name_const('a', null)); drop table t1; --echo # --echo # End of 5.5 tests --echo # --echo # --echo # MDEV-10020 InnoDB NOT IN Query Crash When One Item Is NULL --echo # CREATE TABLE t1 ( a INT(11), b VARCHAR(10), KEY (b) ); INSERT INTO t1 VALUES (1,'x'),(2,'y'),(3,'z'); SELECT * FROM t1 WHERE b NOT IN (NULL, '', 'A'); DROP TABLE t1; --echo # --echo # End of 10.0 tests --echo # --echo # --echo # MDEV-8755 Equal field propagation is not performed any longer for the IN list when multiple comparison types --echo # CREATE TABLE t1 (a INT); INSERT INTO t1 VALUES (1),(2); --echo # Ok to propagate equalities into the left IN argument in case of a single comparison type EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=1 AND a IN (1,2,3); --echo # Ok to propagate equalities into IN () list, even if multiple comparison types EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=1 AND 1 IN (1,a,'3'); --echo # Not Ok to propagate equalities into the left IN argument in case of multiple comparison types EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=1 AND a IN (1,2,'3'); DROP TABLE t1;