[Forums] Advanced Sql: To return all rows when the condition is empty

Actually... 

SELECT {SomeEntity}.* FROM {SomeEntity} WHERE {SomeEntity}.[SomeAttribute] LIKE '%' + @SomeInputParameter + '%'

is what is commonly used... when SomeInputParameter this will become "%%" which matches all possible values. You just need to be aware that you're searching for the value of SomeInputParameter within the contents of SomeAttribute, not for the whole value of SomeAttribute. If SomeInputParameter is "tes" then it would match any of the following values for SomeAttribute: "testing", "hates", "detested".