You can use CASE statement for this. Let us first create a table −
mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Value1 int, Value2 int ); Query OK, 0 rows affected (0.76 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable(Value1,Value2) values(10,5); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable(Value1,Value2) values(20,0); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable(Value1,Value2) values(40,10); Query OK, 1 row affected (0.28 sec) mysql> insert into DemoTable(Value1,Value2) values(50,0); Query OK, 1 row affected (0.12 sec)
Display all records from the table using select statement −
mysql> select *from DemoTable;
This will produce the following output −
+----+--------+--------+ | Id | Value1 | Value2 | +----+--------+--------+ | 1 | 10 | 5 | | 2 | 20 | 0 | | 3 | 40 | 10 | | 4 | 50 | 0 | +----+--------+--------+ 4 rows in set (0.00 sec)
Following is the query to perform multiplication in SELECT depending on column value −
mysql> select Value1,Value2, case when Value2 > 0 then Value1*Value2 else 0 end as Multiplication from DemoTable;
This will produce the following output −
+--------+--------+----------------+ | Value1 | Value2 | Multiplication | +--------+--------+----------------+ | 10 | 5 | 50 | | 20 | 0 | 0 | | 40 | 10 | 400 | | 50 | 0 | 0 | +--------+--------+----------------+ 4 rows in set (0.00 sec)
