How to use MySQL CASE statement while using UPDATE Query?

For using MySQL CASE statement while using UPDATE Query, you can use CASE statement. Let us first create a table −

mysql> create table DemoTable    (    UserId int NOT NULL AUTO_INCREMENT PRIMARY KEY, UserScore int    ); Query OK, 0 rows affected (0.29 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable(UserScore) values(100); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable(UserScore) values(110); Query OK, 1 row affected (0.07 sec) mysql> insert into DemoTable(UserScore) values(120); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable(UserScore) values(200); Query OK, 1 row affected (0.05 sec) mysql> insert into DemoTable(UserScore) values(230); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable(UserScore) values(250); Query OK, 1 row affected (0.03 sec) mysql> insert into DemoTable(UserScore) values(270); Query OK, 1 row affected (0.06 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable;

This will produce the following output −

+--------+-----------+ | UserId | UserScore | +--------+-----------+ |      1 |       100 | |      2 | 110 | |      3 | 120 | |      4 | 200 | |      5 | 230 | |      6 | 250 | |      7 | 270 | +--------+-----------+ 7 rows in set (0.00 sec)

Following is the query to use CASE statement while using UPDATE query −

mysql> update DemoTable set UserScore = CASE WHEN UserScore BETWEEN 100 AND 120 THEN UserScore + 5 WHEN UserScore BETWEEN 130 AND 230 THEN UserScore +10 WHEN UserScore >=250 THEN UserScore * 5 ELSE UserScore END; Query OK, 7 rows affected (0.06 sec) Rows matched: 7 Changed: 7 Warnings: 0

Now you can display all records from the table once again −

mysql> select *from DemoTable;

This will produce the following output −

+--------+-----------+ | UserId | UserScore | +--------+-----------+ | 1 | 105 | | 2 | 115 | | 3 | 125 | | 4 | 210 | | 5 | 240 | | 6 | 1250 | | 7 | 1350 | +--------+-----------+ 7 rows in set (0.00 sec)