SELECT without Table

You can also issue SELECT without a table. For example, you can SELECT an expression or evaluate a built-in function.

mysql> select 1+1;

+-----+

| 1+1 |

+-----+

|   2 |

+-----+

1 row in set (0.00 sec)

mysql> select now();

+---------------------+

| now()               |

+---------------------+

| 2016-05-03 12:40:41 |

+---------------------+

1 row in set (0.00 sec)

mysql> select now(), 1+2;

+---------------------+-----+

| now()               | 1+2 |

+---------------------+-----+

| 2016-05-03 12:40:55 |   3 |

+---------------------+-----+

1 row in set (0.00 sec)