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drop table if exists t1, t2;
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;
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
NULL NULL 1 1 1 1 TRUE TRUE 1 1
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;
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 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,'TRUE') AS `ifnull(null,"TRUE")`,ifnull('TRUE','ERROR') AS `ifnull("TRUE","ERROR")`,isnull((1 / 0)) AS `1/0 is null`,(1 is not null) AS `1 is not null`
select 1 | NULL,1 & NULL,1+NULL,1-NULL;
1 | NULL 1 & NULL 1+NULL 1-NULL
NULL NULL NULL NULL
select NULL=NULL,NULL<>NULL,IFNULL(NULL,1.1)+0,IFNULL(NULL,1) | 0;
NULL=NULL NULL<>NULL IFNULL(NULL,1.1)+0 IFNULL(NULL,1) | 0
NULL NULL 1.1 1
select strcmp("a",NULL),(1<NULL)+0.0,NULL regexp "a",null like "a%","a%" like null;
strcmp("a",NULL) (1<NULL)+0.0 NULL regexp "a" null like "a%" "a%" like null
NULL NULL NULL NULL NULL
select concat("a",NULL),replace(NULL,"a","b"),replace("string","i",NULL),replace("string",NULL,"i"),insert("abc",1,1,NULL),left(NULL,1);
concat("a",NULL) replace(NULL,"a","b") replace("string","i",NULL) replace("string",NULL,"i") insert("abc",1,1,NULL) left(NULL,1)
NULL NULL NULL NULL NULL NULL
select repeat("a",0),repeat("ab",5+5),repeat("ab",-1),reverse(NULL);
repeat("a",0) repeat("ab",5+5) repeat("ab",-1) reverse(NULL)
abababababababababab NULL
select field(NULL,"a","b","c");
field(NULL,"a","b","c")
0
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;
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
0 0 NULL NULL NULL
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;
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 (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`
SELECT NULL AND NULL, 1 AND NULL, NULL AND 1, NULL OR NULL, 0 OR NULL, NULL OR 0;
NULL AND NULL 1 AND NULL NULL AND 1 NULL OR NULL 0 OR NULL NULL OR 0
NULL NULL NULL NULL NULL NULL
SELECT (NULL OR NULL) IS NULL;
(NULL OR NULL) IS NULL
1
select NULL AND 0, 0 and NULL;
NULL AND 0 0 and NULL
0 0
select inet_ntoa(null),inet_aton(null),inet_aton("122.256"),inet_aton("122.226."),inet_aton("");
inet_ntoa(null) inet_aton(null) inet_aton("122.256") inet_aton("122.226.") inet_aton("")
NULL NULL NULL NULL NULL
explain extended select inet_ntoa(null),inet_aton(null),inet_aton("122.256"),inet_aton("122.226."),inet_aton("");
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 inet_ntoa(NULL) AS `inet_ntoa(null)`,inet_aton(NULL) AS `inet_aton(null)`,inet_aton('122.256') AS `inet_aton("122.256")`,inet_aton('122.226.') AS `inet_aton("122.226.")`,inet_aton('') AS `inet_aton("")`
create table t1 (x int);
insert into t1 values (null);
select * from t1 where x != 0;
x
drop table t1;
CREATE TABLE t1 (
indexed_field int default NULL,
KEY indexed_field (indexed_field)
);
INSERT INTO t1 VALUES (NULL),(NULL);
SELECT * FROM t1 WHERE indexed_field=NULL;
indexed_field
SELECT * FROM t1 WHERE indexed_field IS NULL;
indexed_field
NULL
NULL
SELECT * FROM t1 WHERE indexed_field<=>NULL;
indexed_field
NULL
NULL
DROP TABLE t1;
create table t1 (a int, b int) engine=myisam;
insert into t1 values(20,null);
select t2.b, ifnull(t2.b,"this is null") from t1 as t2 left join t1 as t3 on
t2.b=t3.a;
b ifnull(t2.b,"this is null")
NULL this is null
select t2.b, ifnull(t2.b,"this is null") from t1 as t2 left join t1 as t3 on
t2.b=t3.a order by 1;
b ifnull(t2.b,"this is null")
NULL this is null
insert into t1 values(10,null);
select t2.b, ifnull(t2.b,"this is null") from t1 as t2 left join t1 as t3 on
t2.b=t3.a order by 1;
b ifnull(t2.b,"this is null")
NULL this is null
NULL this is null
drop table t1;
CREATE TABLE t1 (a varchar(16) NOT NULL default '', b smallint(6) NOT NULL default 0, c datetime NOT NULL default '0000-00-00 00:00:00', d smallint(6) NOT NULL default 0);
INSERT INTO t1 SET a = "", d= "2003-01-14 03:54:55";
Warnings:
Warning 1265 Data truncated for column 'd' at row 1
UPDATE t1 SET d=1/NULL;
Warnings:
Warning 1048 Column 'd' cannot be null
UPDATE t1 SET d=NULL;
Warnings:
Warning 1048 Column 'd' cannot be null
INSERT INTO t1 (a) values (null);
ERROR 23000: Column 'a' cannot be null
INSERT INTO t1 (a) values (1/null);
ERROR 23000: Column 'a' cannot be null
INSERT INTO t1 (a) values (null),(null);
Warnings:
Warning 1048 Column 'a' cannot be null
Warning 1048 Column 'a' cannot be null
INSERT INTO t1 (b) values (null);
ERROR 23000: Column 'b' cannot be null
INSERT INTO t1 (b) values (1/null);
ERROR 23000: Column 'b' cannot be null
INSERT INTO t1 (b) values (null),(null);
Warnings:
Warning 1048 Column 'b' cannot be null
Warning 1048 Column 'b' cannot be null
INSERT INTO t1 (c) values (null);
ERROR 23000: Column 'c' cannot be null
INSERT INTO t1 (c) values (1/null);
ERROR 23000: Column 'c' cannot be null
INSERT INTO t1 (c) values (null),(null);
Warnings:
Warning 1048 Column 'c' cannot be null
Warning 1048 Column 'c' cannot be null
INSERT INTO t1 (d) values (null);
ERROR 23000: Column 'd' cannot be null
INSERT INTO t1 (d) values (1/null);
ERROR 23000: Column 'd' cannot be null
INSERT INTO t1 (d) values (null),(null);
Warnings:
Warning 1048 Column 'd' cannot be null
Warning 1048 Column 'd' cannot be null
select * from t1;
a b c d
0 0000-00-00 00:00:00 0
0 0000-00-00 00:00:00 0
0 0000-00-00 00:00:00 0
0 0000-00-00 00:00:00 0
0 0000-00-00 00:00:00 0
0 0000-00-00 00:00:00 0
0 0000-00-00 00:00:00 0
0 0000-00-00 00:00:00 0
0 0000-00-00 00:00:00 0
drop table t1;
create table t1 (a int not null, b int not null, index idx(a));
insert into t1 values
(1,1), (2,2), (3,3), (4,4), (5,5), (6,6),
(7,7), (8,8), (9,9), (10,10), (11,11), (12,12);
explain select * from t1 where a between 2 and 3;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range idx idx 4 NULL 1 Using where
explain select * from t1 where a between 2 and 3 or b is null;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range idx idx 4 NULL 1 Using where
drop table t1;
select cast(NULL as signed);
cast(NULL as signed)
NULL
create table t1(i int, key(i));
insert into t1 values(1);
insert into t1 select i*2 from t1;
insert into t1 select i*2 from t1;
insert into t1 select i*2 from t1;
insert into t1 select i*2 from t1;
insert into t1 select i*2 from t1;
insert into t1 select i*2 from t1;
insert into t1 select i*2 from t1;
insert into t1 select i*2 from t1;
insert into t1 select i*2 from t1;
insert into t1 values(null);
explain select * from t1 where i=2 or i is null;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref_or_null i i 5 const # Using where; Using index
select count(*) from t1 where i=2 or i is null;
count(*)
10
alter table t1 change i i int not null;
Warnings:
Warning 1265 Data truncated for column 'i' at row 513
explain select * from t1 where i=2 or i is null;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref i i 4 const 25 Using index
select count(*) from t1 where i=2 or i is null;
count(*)
9
drop table t1;
set names latin2;
create table t1 select
null as c00,
if(1, null, 'string') as c01,
if(0, null, 'string') as c02,
ifnull(null, 'string') as c03,
ifnull('string', null) as c04,
case when 0 then null else 'string' end as c05,
case when 1 then null else 'string' end as c06,
coalesce(null, 'string') as c07,
coalesce('string', null) as c08,
least('string',null) as c09,
least(null, 'string') as c10,
greatest('string',null) as c11,
greatest(null, 'string') as c12,
nullif('string', null) as c13,
nullif(null, 'string') as c14,
trim('string' from null) as c15,
trim(null from 'string') as c16,
substring_index('string', null, 1) as c17,
substring_index(null, 'string', 1) as c18,
elt(1, null, 'string') as c19,
elt(1, 'string', null) as c20,
concat('string', null) as c21,
concat(null, 'string') as c22,
concat_ws('sep', 'string', null) as c23,
concat_ws('sep', null, 'string') as c24,
concat_ws(null, 'string', 'string') as c25,
make_set(3, 'string', null) as c26,
make_set(3, null, 'string') as c27,
export_set(3, null, 'off', 'sep') as c29,
export_set(3, 'on', null, 'sep') as c30,
export_set(3, 'on', 'off', null) as c31,
replace(null, 'from', 'to') as c32,
replace('str', null, 'to') as c33,
replace('str', 'from', null) as c34,
insert('str', 1, 2, null) as c35,
insert(null, 1, 2, 'str') as c36,
lpad('str', 10, null) as c37,
rpad(null, 10, 'str') as c38;
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`c00` binary(0) DEFAULT NULL,
`c01` varchar(6) CHARACTER SET latin2 DEFAULT NULL,
`c02` varchar(6) CHARACTER SET latin2 DEFAULT NULL,
`c03` varchar(6) CHARACTER SET latin2 NOT NULL DEFAULT '',
`c04` varchar(6) CHARACTER SET latin2 DEFAULT NULL,
`c05` varchar(6) CHARACTER SET latin2 DEFAULT NULL,
`c06` varchar(6) CHARACTER SET latin2 DEFAULT NULL,
`c07` varchar(6) CHARACTER SET latin2 DEFAULT NULL,
`c08` varchar(6) CHARACTER SET latin2 DEFAULT NULL,
`c09` varchar(6) CHARACTER SET latin2 DEFAULT NULL,
`c10` varchar(6) CHARACTER SET latin2 DEFAULT NULL,
`c11` varchar(6) CHARACTER SET latin2 DEFAULT NULL,
`c12` varchar(6) CHARACTER SET latin2 DEFAULT NULL,
`c13` varchar(6) CHARACTER SET latin2 DEFAULT NULL,
`c14` char(0) CHARACTER SET latin2 DEFAULT NULL,
`c15` char(0) CHARACTER SET latin2 DEFAULT NULL,
`c16` varchar(6) CHARACTER SET latin2 DEFAULT NULL,
`c17` varchar(6) CHARACTER SET latin2 DEFAULT NULL,
`c18` char(0) CHARACTER SET latin2 DEFAULT NULL,
`c19` varchar(6) CHARACTER SET latin2 DEFAULT NULL,
`c20` varchar(6) CHARACTER SET latin2 DEFAULT NULL,
`c21` varchar(6) CHARACTER SET latin2 DEFAULT NULL,
`c22` varchar(6) CHARACTER SET latin2 DEFAULT NULL,
`c23` varchar(9) CHARACTER SET latin2 DEFAULT NULL,
`c24` varchar(9) CHARACTER SET latin2 DEFAULT NULL,
`c25` varchar(12) CHARACTER SET latin2 DEFAULT NULL,
`c26` varchar(7) CHARACTER SET latin2 DEFAULT NULL,
`c27` varchar(7) CHARACTER SET latin2 DEFAULT NULL,
`c29` varchar(381) CHARACTER SET latin2 DEFAULT NULL,
`c30` varchar(317) CHARACTER SET latin2 DEFAULT NULL,
`c31` varchar(192) CHARACTER SET latin2 DEFAULT NULL,
`c32` char(0) CHARACTER SET latin2 DEFAULT NULL,
`c33` varchar(3) CHARACTER SET latin2 DEFAULT NULL,
`c34` varchar(3) CHARACTER SET latin2 DEFAULT NULL,
`c35` varchar(3) CHARACTER SET latin2 DEFAULT NULL,
`c36` varchar(3) CHARACTER SET latin2 DEFAULT NULL,
`c37` varchar(10) CHARACTER SET latin2 DEFAULT NULL,
`c38` varchar(10) CHARACTER SET latin2 DEFAULT NULL
) ENGINE=PBXT DEFAULT CHARSET=latin1
drop table t1;
select
case 'str' when 'STR' then 'str' when null then 'null' end as c01,
case 'str' when null then 'null' when 'STR' then 'str' end as c02,
field(null, 'str1', 'str2') as c03,
field('str1','STR1', null) as c04,
field('str1', null, 'STR1') as c05,
'string' in ('STRING', null) as c08,
'string' in (null, 'STRING') as c09;
c01 c02 c03 c04 c05 c08 c09
str str 0 1 2 1 1
set names latin1;
create table bug19145a (e enum('a','b','c') default 'b' , s set('x', 'y', 'z') default 'y' ) engine=MyISAM;
create table bug19145b (e enum('a','b','c') default null, s set('x', 'y', 'z') default null) engine=MyISAM;
create table bug19145c (e enum('a','b','c') not null default 'b' , s set('x', 'y', 'z') not null default 'y' ) engine=MyISAM;
create table bug19145setnotnulldefaultnull (e enum('a','b','c') default null, s set('x', 'y', 'z') not null default null) engine=MyISAM;
ERROR 42000: Invalid default value for 's'
create table bug19145enumnotnulldefaultnull (e enum('a','b','c') not null default null, s set('x', 'y', 'z') default null) engine=MyISAM;
ERROR 42000: Invalid default value for 'e'
alter table bug19145a alter column e set default null;
alter table bug19145a alter column s set default null;
alter table bug19145a add column (i int);
alter table bug19145b alter column e set default null;
alter table bug19145b alter column s set default null;
alter table bug19145b add column (i int);
alter table bug19145c alter column e set default null;
ERROR 42000: Invalid default value for 'e'
alter table bug19145c alter column s set default null;
ERROR 42000: Invalid default value for 's'
alter table bug19145c add column (i int);
show create table bug19145a;
Table Create Table
bug19145a CREATE TABLE `bug19145a` (
`e` enum('a','b','c') DEFAULT NULL,
`s` set('x','y','z') DEFAULT NULL,
`i` int(11) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
show create table bug19145b;
Table Create Table
bug19145b CREATE TABLE `bug19145b` (
`e` enum('a','b','c') DEFAULT NULL,
`s` set('x','y','z') DEFAULT NULL,
`i` int(11) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
show create table bug19145c;
Table Create Table
bug19145c CREATE TABLE `bug19145c` (
`e` enum('a','b','c') NOT NULL DEFAULT 'b',
`s` set('x','y','z') NOT NULL DEFAULT 'y',
`i` int(11) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table bug19145a;
drop table bug19145b;
drop table bug19145c;
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