If Then Else

Keyword IF ... THEN ... ELSE

Syntax:

    IF expression THEN statement1 [ELSE statement2]

For example:

    IF EXISTS(SELECT * FROM one WHERE a=10) 
       UPDATE one SET b = 200 WHERE a=10
    ELSE 
       INSERT INTO one VALUES (5,500);

Try this AlaSQL example in jsFiddle.

See also: CASE