mariadb/mysql-test/t/null.test

#
# Testing of NULL in a lot of different places
#

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;
select 1 | NULL,1 & NULL,1+NULL,1-NULL;
select NULL=NULL,NULL<>NULL,IFNULL(NULL,1.1)+0,IFNULL(NULL,1) | 0;
select strcmp("a",NULL),(1<NULL)+0.0,NULL regexp "a",null like "a%","a%" like 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);
select repeat("a",0),repeat("ab",5+5),repeat("ab",-1),reverse(NULL);
select field(NULL,"a","b","c");
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;
SELECT NULL AND NULL, 1 AND NULL, NULL AND 1, NULL OR NULL, 0 OR NULL, NULL OR 0;
SELECT (NULL OR NULL) IS NULL;
select NULL AND 0, 0 and NULL;
select inet_ntoa(null),inet_aton(null),inet_aton("122.256"),inet_aton("122.226."),inet_aton("");

drop table if exists t1;
create table t1 (x int);
insert into t1 values (null);
select * from t1 where x != 0;
drop table t1;

#
# Test problem med index on NULL columns and testing with =NULL;
#

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;
SELECT * FROM t1 WHERE indexed_field IS NULL;
SELECT * FROM t1 WHERE indexed_field<=>NULL;
DROP TABLE t1;