MySQL query to replace only the NULL values from the table?
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)
Published on 30-Sep-2019 08:21:32
