How to cast to string the result of an inner query?

Question

I have the following query (which should return a scalar/numeric), But I still get a sql error.

I am using mysql 5.0.77 or 5.1.37

SELECT CAST(SELECT COUNT(*) FROM t1 AS VARCHAR)

Answer 1

SELECT CAST(t.x AS VARCHAR) FROM (SELECT COUNT(*) AS x FROM t1) t; should work

Answer 2

Why not use:

SELECT CAST(COUNT(*) AS VARCHAR) FROM t1

Answer 3

You can't cast to VARCHAR. Try CHAR(n) instead:

SELECT CAST((SELECT COUNT(*) FROM t1) AS CHAR(10))

A list of the types you can cast to can be found here.