SQL Statements in Stored Functions

You can include SQL statements within stored functions , although you should be very careful about including SQL statements in a stored function that might itself be used inside a SQL statement (more on that later).

However, you cannot return a result set from a stored function: trying to create a stored function that contains a SELECT statement without an INTO clause will result in a 1415 error, as shown in Example 10-5.

Example 10-5. Stored functions cannot return result sets

mysql> CREATE FUNCTION test_func( )
 -> RETURNS INT
 -> BEGIN
 -> SELECT 'Hello World';
 -> RETURN 1;
 -> END;$$
ERROR 1415 (0A000): Not allowed to return a result set from a function