To check for NULL, use the IS NULL. For empty values, you need to check with an empty string. We will now see an example.
Let us first create a table −
mysql> create table DemoTable691( PlayerId int NOT NULL AUTO_INCREMENT PRIMARY KEY, PlayerName varchar(100), PlayerScore int ); Query OK, 0 rows affected (0.56 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable691(PlayerName,PlayerScore) values('Robert',56); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable691(PlayerName,PlayerScore) values('David',89); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable691(PlayerName,PlayerScore) values('',98); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable691(PlayerName,PlayerScore) values(null,71); Query OK, 1 row affected (0.17 sec)
Display all records from the table using select statement −
mysql> select *from DemoTable691;
This will produce the following output −
+----------+------------+-------------+ | PlayerId | PlayerName | PlayerScore | +----------+------------+-------------+ | 1 | Robert | 56 | | 2 | David | 89 | | 3 | | 98 | | 4 | NULL | 71 | +----------+------------+-------------+ 4 rows in set (0.00 sec)
Following is the MySQL query to display empty and NULL value together −
mysql> select *from DemoTable691 where PlayerName IS NULL OR PlayerName='';
This will produce the following output −
+----------+------------+-------------+ | PlayerId | PlayerName | PlayerScore | +----------+------------+-------------+ | 3 | | 98 | | 4 | NULL | 71 | +----------+------------+-------------+ 2 rows in set (0.00 sec)