A function can have a single-line body that is comprised of a RETURN statement. Alternatively, multiple statements (compound statements) can be specified inside the BEGIN ATOMIC and END statements. Note that there can be more than one RETURN statement in the body. The following syntax is used for a RETURN statement: 
RETURN <expression>

where

expression
is the argument that determines the value to be returned.
For example, the following function demonstrates using a RETURN statement in a compound statement: 
// This function returns a time one hour before the event starts
RETURNS TIMESTAMP
BEGIN ATOMIC
    DECLARE max_event TIMESTAMP;
    SET max_event = SELECT MAX(start_time) FROM events WHERE type = e_type;
    RETURN max_event - 1 HOUR;
END

The next example returns same results as the prior without using the compound statements body: 

CREATE FUNCTION an_hour_before_max (e_type INTEGER)
RETURNS TIMESTAMP
    RETURN (SELECT MAX(start_time) FROM events WHERE type = e_type) - 1 HOUR
The following example demonstrates a function that uses the RETURN TABLE syntax to return a table: 
CREATE FUNCTION alice_and_friends(ignore INTEGER)
RETURNS TABLE(id INTEGER, name VARCHAR(32))
READS SQL DATA
BEGIN ATOMIC
//This function returns a table value. The value can be used by the caller 
//anywhere a TABLE clause would go, like SELECT * FROM alice_and_friends(3);
    DECLARE TABLE temptable (id INTEGER, name VARCHAR(32));
    INSERT INTO temptable VALUES (1, 'Alice');
    INSERT INTO temptable VALUES (2, 'Bob');
    INSERT INTO temptable VALUES (3, 'Chuck');
    RETURN TABLE(SELECT * FROM temptable WHERE id != ignore);
END;