test-example-projects/c++_projects/280w-mysql-8.0.18/mysql-test/t/func_isnull.test

#
# test of ISNULL()
#

--disable_warnings
drop table if exists t1;
--enable_warnings

create table t1 (id int auto_increment primary key not null, mydate date not null);
insert into t1 values (0,"2002-05-01"),(0,"2002-05-01"),(0,"2002-05-01");
flush tables;
select * from t1 where isnull(to_days(mydate));
drop table t1;

# End of 4.1 tests

--echo #
--echo # Bug#53933 crash when using uncacheable subquery in the having clause of outer query
--echo #

CREATE TABLE t1 (f1 INT);
INSERT INTO t1 VALUES (0),(0);

SELECT ISNULL((SELECT GET_LOCK('Bug#53933', 0) FROM t1 GROUP BY f1)) AS f2
FROM t1 GROUP BY f1 HAVING f2 = f2;
SELECT RELEASE_LOCK('Bug#53933');

DROP TABLE t1;

--echo End of 5.0 tests

#
# Bug #41371    Select returns 1 row with condition "col is not null and col is null"
#

CREATE TABLE t1 (id INTEGER UNSIGNED NOT NULL AUTO_INCREMENT, PRIMARY KEY(id));
INSERT INTO t1( id ) VALUES ( NULL );
SELECT t1.id  FROM t1  WHERE (id  is not null and id is null );
DROP TABLE t1;

# End of 5.1 tests

--echo #
--echo # Bug#29027883 INCORRECT RESULT OF LEFT JOIN
--echo #

# test the special, documented behaviour of "not-nullable-DATE-column
# IS NULL"

CREATE TABLE t1 (
pk int NOT NULL,
col_int_key INT NOT NULL,
col_date_key date NOT NULL,
PRIMARY KEY (pk),
KEY col_int_key (col_int_key),
KEY col_date_key (col_date_key)
) ENGINE=MyISAM;
INSERT IGNORE INTO t1 VALUES (14,4,'0000-00-00'), (15,2,'2003-01-13'),
(16,5,'2006-07-07'), (17,3,'0000-00-00');
CREATE TABLE t2 (
pk INT NOT NULL,
PRIMARY KEY (pk)
) ENGINE=MyISAM;
INSERT INTO t2 VALUES (1), (2), (3);

CREATE TABLE t3(pk INT NOT NULL);

INSERT INTO t3 VALUES(3),(3);

select * from t3 left join
(t2 outr2 join t2 outr join t1)
on (outr.pk = t3.pk) and (t1.col_int_key = t3.pk) and isnull(t1.col_date_key)
and (outr2.pk <> t3.pk) ;

select * from t3 join
(t2 outr2 join t2 outr join t1)
on (outr.pk = t3.pk) and (t1.col_int_key = t3.pk) and isnull(t1.col_date_key)
and (outr2.pk <> t3.pk) ;

delete from t3;
INSERT INTO t3 VALUES(3);

# Special behaviour is:

# enabled in WHERE
let $query=
select * from t3, t1 where t1.col_date_key is null;

eval EXPLAIN $query;
eval $query;

# disabled in [LEFT] JOIN ON
let $query=
select * from t3 join t1 on t1.col_date_key is null;

eval EXPLAIN $query;
eval $query;

let $query=
select * from t3 left join t1 on t1.col_date_key is null;

eval EXPLAIN $query;
eval $query;

# Combine both:
let $query=
select * from t3 left join t1 on t1.col_date_key is null
where t1.col_date_key is null;

eval EXPLAIN $query;
eval $query;

# disabled in IS NOT NULL
let $query=
select * from t3, t1 where t1.col_date_key is not null;

eval EXPLAIN $query;
eval $query;

# disabled in NOT (IS NULL)
let $query=
select * from t3, t1 where not (t1.col_date_key is null);

eval EXPLAIN $query;
eval $query;

# enabled in (IS NULL) IS TRUE
let $query=
select * from t3, t1 where (t1.col_date_key is null) is true;

eval EXPLAIN $query;
eval $query;

DROP TABLE t1,t2,t3;