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c5e6941e75
the result takes its charset/collation attributes from the character string, e.g. SELECT func(NULL, _latin2'string') now returns a latin2 result. This is done by introducing a new derivation (aka coercibility) level DERIVATION_IGNORABLE, which is used with Item_null. 2. 'Pure' NULL is now BINARY(0), not CHAR(0). I.e. NULL is now more typeless. mysql-test/r/metadata.result: Fixing test results: CHAR(0) -> BINARY(0) for NULLs mysql-test/r/null.result: Testing mixing NULL with a character string with a number of functions. mysql-test/r/ps_2myisam.result: Fixing test results: CHAR(0) -> BINARY(0) for NULLs mysql-test/r/ps_3innodb.result: Fixing test results: CHAR(0) -> BINARY(0) for NULLs mysql-test/r/ps_4heap.result: Fixing test results: CHAR(0) -> BINARY(0) for NULLs mysql-test/r/ps_5merge.result: Fixing test results: CHAR(0) -> BINARY(0) for NULLs mysql-test/r/ps_6bdb.result: Fixing test results: CHAR(0) -> BINARY(0) for NULLs mysql-test/r/ps_7ndb.result: Fixing test results: CHAR(0) -> BINARY(0) for NULLs mysql-test/t/null.test: Testing mixing NULL with a character string with a number of functions. sql/item.cc: New derivation level. sql/item.h: New derivation level.
272 lines
12 KiB
Plaintext
272 lines
12 KiB
Plaintext
drop table if exists t1;
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select null,\N,isnull(null),isnull(1/0),isnull(1/0 = null),ifnull(null,1),ifnull(null,"TRUE"),ifnull("TRUE","ERROR"),1/0 is null,1 is not null;
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NULL NULL isnull(null) isnull(1/0) isnull(1/0 = null) ifnull(null,1) ifnull(null,"TRUE") ifnull("TRUE","ERROR") 1/0 is null 1 is not null
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NULL NULL 1 1 1 1 TRUE TRUE 1 1
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explain extended select null,\N,isnull(null),isnull(1/0),isnull(1/0 = null),ifnull(null,1),ifnull(null,"TRUE"),ifnull("TRUE","ERROR"),1/0 is null,1 is not null;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL No tables used
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Warnings:
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Note 1003 select NULL AS `NULL`,NULL AS `NULL`,isnull(NULL) AS `isnull(null)`,isnull((1 / 0)) AS `isnull(1/0)`,isnull(((1 / 0) = NULL)) AS `isnull(1/0 = null)`,ifnull(NULL,1) AS `ifnull(null,1)`,ifnull(NULL,_latin1'TRUE') AS `ifnull(null,"TRUE")`,ifnull(_latin1'TRUE',_latin1'ERROR') AS `ifnull("TRUE","ERROR")`,isnull((1 / 0)) AS `1/0 is null`,(1 is not null) AS `1 is not null`
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select 1 | NULL,1 & NULL,1+NULL,1-NULL;
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1 | NULL 1 & NULL 1+NULL 1-NULL
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NULL NULL NULL NULL
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select NULL=NULL,NULL<>NULL,IFNULL(NULL,1.1)+0,IFNULL(NULL,1) | 0;
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NULL=NULL NULL<>NULL IFNULL(NULL,1.1)+0 IFNULL(NULL,1) | 0
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NULL NULL 1.1 1
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select strcmp("a",NULL),(1<NULL)+0.0,NULL regexp "a",null like "a%","a%" like null;
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strcmp("a",NULL) (1<NULL)+0.0 NULL regexp "a" null like "a%" "a%" like null
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NULL NULL NULL NULL NULL
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select concat("a",NULL),replace(NULL,"a","b"),replace("string","i",NULL),replace("string",NULL,"i"),insert("abc",1,1,NULL),left(NULL,1);
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concat("a",NULL) replace(NULL,"a","b") replace("string","i",NULL) replace("string",NULL,"i") insert("abc",1,1,NULL) left(NULL,1)
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NULL NULL NULL NULL NULL NULL
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select repeat("a",0),repeat("ab",5+5),repeat("ab",-1),reverse(NULL);
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repeat("a",0) repeat("ab",5+5) repeat("ab",-1) reverse(NULL)
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abababababababababab NULL
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select field(NULL,"a","b","c");
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field(NULL,"a","b","c")
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0
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select 2 between null and 1,2 between 3 AND NULL,NULL between 1 and 2,2 between NULL and 3, 2 between 1 AND null;
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2 between null and 1 2 between 3 AND NULL NULL between 1 and 2 2 between NULL and 3 2 between 1 AND null
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0 0 NULL NULL NULL
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explain extended select 2 between null and 1,2 between 3 AND NULL,NULL between 1 and 2,2 between NULL and 3, 2 between 1 AND null;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL No tables used
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Warnings:
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Note 1003 select (2 between NULL and 1) AS `2 between null and 1`,(2 between 3 and NULL) AS `2 between 3 AND NULL`,(NULL between 1 and 2) AS `NULL between 1 and 2`,(2 between NULL and 3) AS `2 between NULL and 3`,(2 between 1 and NULL) AS `2 between 1 AND null`
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SELECT NULL AND NULL, 1 AND NULL, NULL AND 1, NULL OR NULL, 0 OR NULL, NULL OR 0;
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NULL AND NULL 1 AND NULL NULL AND 1 NULL OR NULL 0 OR NULL NULL OR 0
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NULL NULL NULL NULL NULL NULL
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SELECT (NULL OR NULL) IS NULL;
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(NULL OR NULL) IS NULL
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1
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select NULL AND 0, 0 and NULL;
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NULL AND 0 0 and NULL
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0 0
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select inet_ntoa(null),inet_aton(null),inet_aton("122.256"),inet_aton("122.226."),inet_aton("");
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inet_ntoa(null) inet_aton(null) inet_aton("122.256") inet_aton("122.226.") inet_aton("")
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NULL NULL NULL NULL NULL
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explain extended select inet_ntoa(null),inet_aton(null),inet_aton("122.256"),inet_aton("122.226."),inet_aton("");
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL No tables used
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Warnings:
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Note 1003 select inet_ntoa(NULL) AS `inet_ntoa(null)`,inet_aton(NULL) AS `inet_aton(null)`,inet_aton(_latin1'122.256') AS `inet_aton("122.256")`,inet_aton(_latin1'122.226.') AS `inet_aton("122.226.")`,inet_aton(_latin1'') AS `inet_aton("")`
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create table t1 (x int);
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insert into t1 values (null);
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select * from t1 where x != 0;
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x
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drop table t1;
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CREATE TABLE t1 (
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indexed_field int default NULL,
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KEY indexed_field (indexed_field)
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);
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INSERT INTO t1 VALUES (NULL),(NULL);
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SELECT * FROM t1 WHERE indexed_field=NULL;
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indexed_field
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SELECT * FROM t1 WHERE indexed_field IS NULL;
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indexed_field
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NULL
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NULL
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SELECT * FROM t1 WHERE indexed_field<=>NULL;
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indexed_field
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NULL
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NULL
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DROP TABLE t1;
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create table t1 (a int, b int) engine=myisam;
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insert into t1 values(20,null);
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select t2.b, ifnull(t2.b,"this is null") from t1 as t2 left join t1 as t3 on
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t2.b=t3.a;
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b ifnull(t2.b,"this is null")
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NULL this is null
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select t2.b, ifnull(t2.b,"this is null") from t1 as t2 left join t1 as t3 on
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t2.b=t3.a order by 1;
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b ifnull(t2.b,"this is null")
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NULL this is null
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insert into t1 values(10,null);
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select t2.b, ifnull(t2.b,"this is null") from t1 as t2 left join t1 as t3 on
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t2.b=t3.a order by 1;
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b ifnull(t2.b,"this is null")
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NULL this is null
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NULL this is null
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drop table t1;
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CREATE TABLE t1 (a varchar(16) NOT NULL, b smallint(6) NOT NULL, c datetime NOT NULL, d smallint(6) NOT NULL);
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INSERT INTO t1 SET a = "", d= "2003-01-14 03:54:55";
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Warnings:
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Warning 1265 Data truncated for column 'd' at row 1
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UPDATE t1 SET d=1/NULL;
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Warnings:
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Warning 1265 Data truncated for column 'd' at row 1
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UPDATE t1 SET d=NULL;
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Warnings:
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Warning 1263 Data truncated; NULL supplied to NOT NULL column 'd' at row 1
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INSERT INTO t1 (a) values (null);
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ERROR 23000: Column 'a' cannot be null
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INSERT INTO t1 (a) values (1/null);
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ERROR 23000: Column 'a' cannot be null
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INSERT INTO t1 (a) values (null),(null);
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Warnings:
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Warning 1263 Data truncated; NULL supplied to NOT NULL column 'a' at row 1
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Warning 1263 Data truncated; NULL supplied to NOT NULL column 'a' at row 2
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INSERT INTO t1 (b) values (null);
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ERROR 23000: Column 'b' cannot be null
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INSERT INTO t1 (b) values (1/null);
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ERROR 23000: Column 'b' cannot be null
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INSERT INTO t1 (b) values (null),(null);
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Warnings:
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Warning 1263 Data truncated; NULL supplied to NOT NULL column 'b' at row 1
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Warning 1263 Data truncated; NULL supplied to NOT NULL column 'b' at row 2
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INSERT INTO t1 (c) values (null);
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ERROR 23000: Column 'c' cannot be null
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INSERT INTO t1 (c) values (1/null);
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ERROR 23000: Column 'c' cannot be null
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INSERT INTO t1 (c) values (null),(null);
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Warnings:
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Warning 1263 Data truncated; NULL supplied to NOT NULL column 'c' at row 1
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Warning 1263 Data truncated; NULL supplied to NOT NULL column 'c' at row 2
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INSERT INTO t1 (d) values (null);
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ERROR 23000: Column 'd' cannot be null
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INSERT INTO t1 (d) values (1/null);
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ERROR 23000: Column 'd' cannot be null
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INSERT INTO t1 (d) values (null),(null);
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Warnings:
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Warning 1263 Data truncated; NULL supplied to NOT NULL column 'd' at row 1
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Warning 1263 Data truncated; NULL supplied to NOT NULL column 'd' at row 2
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select * from t1;
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a b c d
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0 0000-00-00 00:00:00 0
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0 0000-00-00 00:00:00 0
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0 0000-00-00 00:00:00 0
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0 0000-00-00 00:00:00 0
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0 0000-00-00 00:00:00 0
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0 0000-00-00 00:00:00 0
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0 0000-00-00 00:00:00 0
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0 0000-00-00 00:00:00 0
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0 0000-00-00 00:00:00 0
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drop table t1;
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create table t1 (a int not null, b int not null, index idx(a));
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insert into t1 values
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(1,1), (2,2), (3,3), (4,4), (5,5), (6,6),
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(7,7), (8,8), (9,9), (10,10), (11,11), (12,12);
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explain select * from t1 where a between 2 and 3;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 range idx idx 4 NULL 2 Using where
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explain select * from t1 where a between 2 and 3 or b is null;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 range idx idx 4 NULL 2 Using where
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drop table t1;
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select cast(NULL as signed);
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cast(NULL as signed)
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NULL
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create table t1(i int, key(i));
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insert into t1 values(1);
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insert into t1 select i*2 from t1;
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insert into t1 select i*2 from t1;
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insert into t1 select i*2 from t1;
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insert into t1 select i*2 from t1;
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insert into t1 select i*2 from t1;
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insert into t1 select i*2 from t1;
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insert into t1 select i*2 from t1;
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insert into t1 select i*2 from t1;
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insert into t1 select i*2 from t1;
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explain select * from t1 where i=2 or i is null;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ref_or_null i i 5 const 10 Using where; Using index
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alter table t1 change i i int not null;
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explain select * from t1 where i=2 or i is null;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ref i i 4 const 7 Using where; Using index
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drop table t1;
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set names latin2;
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create table t1 select
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null as c00,
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if(1, null, 'string') as c01,
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if(0, null, 'string') as c02,
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ifnull(null, 'string') as c03,
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ifnull('string', null) as c04,
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case when 0 then null else 'string' end as c05,
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case when 1 then null else 'string' end as c06,
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coalesce(null, 'string') as c07,
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coalesce('string', null) as c08,
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least('string',null) as c09,
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least(null, 'string') as c10,
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greatest('string',null) as c11,
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greatest(null, 'string') as c12,
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nullif('string', null) as c13,
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nullif(null, 'string') as c14,
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trim('string' from null) as c15,
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trim(null from 'string') as c16,
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substring_index('string', null, 1) as c17,
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substring_index(null, 'string', 1) as c18,
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elt(1, null, 'string') as c19,
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elt(1, 'string', null) as c20,
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concat('string', null) as c21,
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concat(null, 'string') as c22,
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concat_ws('sep', 'string', null) as c23,
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concat_ws('sep', null, 'string') as c24,
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concat_ws(null, 'string', 'string') as c25,
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make_set(3, 'string', null) as c26,
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make_set(3, null, 'string') as c27,
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export_set(3, null, 'off', 'sep') as c29,
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export_set(3, 'on', null, 'sep') as c30,
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export_set(3, 'on', 'off', null) as c31,
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replace(null, 'from', 'to') as c32,
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replace('str', null, 'to') as c33,
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replace('str', 'from', null) as c34,
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insert('str', 1, 2, null) as c35,
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insert(null, 1, 2, 'str') as c36,
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lpad('str', 10, null) as c37,
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rpad(null, 10, 'str') as c38;
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show create table t1;
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Table Create Table
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t1 CREATE TABLE `t1` (
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`c00` binary(0) default NULL,
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`c01` varchar(6) character set latin2 default NULL,
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`c02` varchar(6) character set latin2 default NULL,
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`c03` varchar(6) character set latin2 NOT NULL default '',
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`c04` varchar(6) character set latin2 default NULL,
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`c05` varchar(6) character set latin2 default NULL,
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`c06` varchar(6) character set latin2 default NULL,
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`c07` varchar(6) character set latin2 default NULL,
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`c08` varchar(6) character set latin2 default NULL,
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`c09` varchar(6) character set latin2 NOT NULL default '',
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`c10` varchar(6) character set latin2 NOT NULL default '',
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`c11` varchar(6) character set latin2 NOT NULL default '',
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`c12` varchar(6) character set latin2 NOT NULL default '',
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`c13` varchar(6) character set latin2 default NULL,
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`c14` char(0) character set latin2 default NULL,
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`c15` char(0) character set latin2 default NULL,
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`c16` varchar(6) character set latin2 default NULL,
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`c17` varchar(6) character set latin2 default NULL,
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`c18` char(0) character set latin2 default NULL,
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`c19` varchar(6) character set latin2 default NULL,
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`c20` varchar(6) character set latin2 default NULL,
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`c21` varchar(6) character set latin2 default NULL,
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`c22` varchar(6) character set latin2 default NULL,
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`c23` varchar(9) character set latin2 default NULL,
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`c24` varchar(9) character set latin2 default NULL,
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`c25` varchar(12) character set latin2 default NULL,
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`c26` varchar(7) character set latin2 default NULL,
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`c27` varchar(7) character set latin2 default NULL,
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`c29` longtext character set latin2,
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`c30` longtext character set latin2,
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`c31` varchar(192) character set latin2 default NULL,
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`c32` char(0) character set latin2 default NULL,
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`c33` char(3) character set latin2 default NULL,
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`c34` char(3) character set latin2 default NULL,
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`c35` char(3) character set latin2 default NULL,
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`c36` char(3) character set latin2 default NULL,
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`c37` varchar(10) character set latin2 default NULL,
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`c38` varchar(10) character set latin2 default NULL
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) ENGINE=MyISAM DEFAULT CHARSET=latin1
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drop table t1;
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select
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case 'str' when 'STR' then 'str' when null then 'null' end as c01,
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case 'str' when null then 'null' when 'STR' then 'str' end as c02,
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field(null, 'str1', 'str2') as c03,
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field('str1','STR1', null) as c04,
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field('str1', null, 'STR1') as c05,
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'string' in ('STRING', null) as c08,
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'string' in (null, 'STRING') as c09;
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c01 c02 c03 c04 c05 c08 c09
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str str 0 1 2 1 1
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set names latin1;
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