moshno icpol"zovat" Dynamic SQL , naprimer tak :

DECLARE @SQLString varchar(8000)
declare @Email varchar(75) = NULL, -- User's email , for exp
SELECT @SQLstring = 'SELECT u.a, u.b, u.a '
SELECT @SQLString = @SQLString + ' FROM table1 u'
SELECT @SQLString = @SQLString + 'JOIN table2 ua on ua.b = u.b '
SELECT @SQLstring = @SQLString + ' AND a like ''%' + @Email + '%'''
PRINT @SQLstring ( ---for testing )
EXEC ( @SQLstring )