Swap data between two columns in MySQL?


To swap data between two columns in MySQL, use the concept of variable. Let us first create a table. Here, we will swap Name1 with Name2 −

mysql> create table DemoTable
   -> (
   -> Name1 varchar(100),
   -> Name2 varchar(100)
   -> );
Query OK, 0 rows affected (0.58 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable values('John Smith','Chris Brown');
Query OK, 1 row affected (0.10 sec)

mysql> insert into DemoTable values('David Miller','Jone Doe');
Query OK, 1 row affected (0.16 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable;

This will produce the following output −

+--------------+-------------+
| Name1        | Name2       |
+--------------+-------------+
| John Smith   | Chris Brown |
| David Miller | Jone Doe    |
+--------------+-------------+
2 rows in set (0.00 sec)

Following is the query to swap data between two columns in MySQL −

mysql> update DemoTable
   -> SET Name1=(@tmpName:=Name1), Name1 = Name2, Name2 = @tmpName;
Query OK, 2 rows affected (0.13 sec)
Rows matched: 2 Changed: 2 Warnings: 0

Let us check table records once again −

mysql> select *from DemoTable;

This will produce the following output −

+-------------+--------------+
| Name1       | Name2        |
+-------------+--------------+
| Chris Brown | John Smith   |
| Jone Doe    | David Miller |
+-------------+--------------+
2 rows in set (0.00 sec)
raja
Published on 12-Jul-2019 16:11:23
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