Web-automation.ru

Решение:

DECLARE @input VARCHAR(11) = '2323'
select CAST(CASE WHEN @input NOT LIKE '%[^0-9]%' THEN @input END AS INT)

DECLARE @input2 VARCHAR(11) = '23.23'
select CAST(CASE WHEN @input2 NOT LIKE '%[^0-9.]%' THEN @input2 END AS float)