Update One Column Data to Another Column in MySQL

To update one column data to another column, you can use UPDATE command. 

Let us first create a table −

mysql> create table DemoTable
(
   UserId int NOT NULL AUTO_INCREMENT PRIMARY KEY,
   UserFirstName varchar(20),
   ListOfName varchar(20)
);
Query OK, 0 rows affected (0.59 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable(UserFirstName,ListOfName) values('John','Larry');
Query OK, 1 row affected (0.29 sec)
mysql> insert into DemoTable(UserFirstName,ListOfName) values('Carol',null);
Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable(UserFirstName,ListOfName) values('David','Sam');
Query OK, 1 row affected (0.22 sec)
mysql> insert into DemoTable(UserFirstName,ListOfName) values('Bob',null);
Query OK, 1 row affected (0.25 sec)
mysql> insert into DemoTable(UserFirstName,ListOfName) values(null,null);
Query OK, 1 row affected (0.18 sec)

Following is the query to display all records from the table using select statement −

mysql> select *from DemoTable;

This will produce the following output −

+--------+---------------+------------+
| UserId | UserFirstName | ListOfName |
+--------+---------------+------------+
| 1      | John          | Larry      |
| 2      | Carol         | NULL       |
| 3      | David         | Sam        |
| 4      | Bob           | NULL       |
| 5      | NULL          | NULL       |
+--------+---------------+------------+
5 rows in set (0.00 sec)

Following is the query to update one column data with another column if the 2nd column is NOT NULL −

mysql> update DemoTable set UserFirstName=ListOfName where ListOfName is not null;
Query OK, 2 rows affected (0.26 sec)
Rows matched: 2 Changed: 2 Warnings: 0

Let us check the column UserFirstName is updated or not.

mysql> select *from DemoTable;

This will produce the following output −

+--------+---------------+------------+
| UserId | UserFirstName | ListOfName |
+--------+---------------+------------+
| 1      | Larry         | Larry      |
| 2      | Carol         | NULL       |
| 3      | Sam           | Sam        |
| 4      | Bob           | NULL       |
| 5      | NULL          | NULL       |
+--------+---------------+------------+
5 rows in set (0.00 sec)