Set conditions while adding column values in MySQL?

To set conditions while adding column values, use MySQL IF(). Let us first create a table −

mysql> create table DemoTable    -> (    -> Value1 int,    -> Value2 int,    -> Value3 int    -> ); Query OK, 0 rows affected (0.64 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable values(10,20,-30); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values(50,60,90); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values(100,200,400); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable values(30,40,-50); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(70,80,-1); Query OK, 1 row affected (0.24 sec)

Display all records from the table using select statement −

mysql> select * from DemoTable;

This will produce the following output −

+--------+--------+--------+ | Value1 | Value2 | Value3 | +--------+--------+--------+ |     10 |     20 |    -30 | |     50 |     60 |     90 | |    100 |    200 |    400 | |     30 |     40 |    -50 | |     70 |     80 |     -1 | +--------+--------+--------+ 5 rows in set (0.00 sec)

Here is the query to set conditions while adding column values −

mysql> select Value1+Value2+if(Value3 > 0,Value3,0) from DemoTable;

This will produce the following output −

+---------------------------------------+ | Value1+Value2+if(Value3 > 0,Value3,0) | +---------------------------------------+ |                                    30 | |                                   200 | |                                   700 | |                                    70 | |                                   150 | +---------------------------------------+ 5 rows in set (0.00 sec)