mysql> select * from test;
+---+---+
| a | b |
+---+---+
| a | a |
| a | a |
| a | b |
| b | b |
+---+---+
4 rows in set (0.00 sec)

mysql> SELECT * from test;
+---+---+
| a | b |
+---+---+
| a | a |
| a | a |
| a | b |
| b | b |
+---+---+
4 rows in set (0.00 sec)

mysql> SELECT
    ->
    -> ;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1
mysql> SELECT * from test;
+---+---+
| a | b |
+---+---+
| a | a |
| a | a |
| a | b |
| b | b |
+---+---+
4 rows in set (0.00 sec)