MySQL query to replace only the NULL values from the table?

MySQLMySQLi Database

For this, you can use the property IS NULL for null values in MySQL. Let us first create a table −

mysql> create table DemoTable
(
   Name varchar(100)
);
Query OK, 0 rows affected (0.53 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable values('Robert');
Query OK, 1 row affected (0.23 sec)
mysql> insert into DemoTable values(null);
Query OK, 1 row affected (0.10 sec)
mysql> insert into DemoTable values('David');
Query OK, 1 row affected (0.12 sec)
mysql> insert into DemoTable values(null);
Query OK, 1 row affected (0.11 sec)
mysql> insert into DemoTable values('Robert');
Query OK, 1 row affected (0.18 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable;

This will produce the following output −

+--------+
| Name   |
+--------+
| Robert |
| NULL   |
| David  |
| NULL   |
| Robert |
+--------+
5 rows in set (0.00 sec)

Following is the query to replace null values from the table −

mysql> update DemoTable set Name=IF(Name IS NULL,'Please Enter a Name',Name);
Query OK, 2 rows affected (0.09 sec)
Rows matched: 5 Changed: 2 Warnings: 0

Let us check the table records once again −

mysql> select *from DemoTable;

This will produce the following output −

+---------------------+
| Name                |
+---------------------+
| Robert              |
| Please Enter a Name |
| David               |
| Please Enter a Name |
| Robert              |
+---------------------+
5 rows in set (0.00 sec)
raja
Published on 30-Sep-2019 08:21:32
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