MYSQL if a select query returns 0 rows then another select query?

Question

if select * from table where x=1 returns 0 rows, then I need select * from table where x=2 [or some other query]. Is it possible to do this in a si

Answer 1

The simplest explanation is that:

SELECT IF(1 = 2,'true','false'); --> false
SELECT IF(1 = 1,' true','false'); --> true
SELECT IF(1 = 2,' true','false'), IF(1 = 1,' true','false'); --> false | true

The 'if' statement give some functionality to selected values. The structure is something like this:

SELECT IF(), ...... FROM 

A great explanation can be found here.