Syntax error Perform MySQL SELECT on fields containing null values?

Perform MySQL SELECT on fields containing null values?



To check for NULL values in SELECT, use MySQL NULL. Let us first create a table −

mysql> create table DemoTable1455
   -> (
   -> Name varchar(20)
   -> );
Query OK, 0 rows affected (0.47 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable1455 values('John');
Query OK, 1 row affected (0.22 sec)
mysql> insert into DemoTable1455 values(NULL);
Query OK, 1 row affected (0.12 sec)
mysql> insert into DemoTable1455 values('');
Query OK, 1 row affected (0.19 sec)

Display all records from the table using select statement −

mysql> select * from DemoTable1455;

This will produce the following output −

+------+
| Name |
+------+
| John |
| NULL |
|      |
+------+
3 rows in set (0.00 sec)

Following is the query to perform MySQL select on fields containing null values −

mysql> select * from DemoTable1455 where Name <> 'John' or Name is null;

This will produce the following output −

+------+
| Name |
+------+
| NULL |
|      |
+------+
2 rows in set (0.00 sec)
Updated on: 2019-12-10T06:18:58+05:30

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