SQL if select statement returns no rows then perform alternative select statement

Question

Basically, what syntex would allow me to achieve the title statement?

If (select statement 1) returns 0 rows THEN (select statement 2) else (select statement 3)
         


        

Answer 1

Here you go...

IF ((select count(*) from table1)= 0)
BEGIN
Select * from table2
END
ELSE
BEGIN
SELECT * from table3
END