that's not the problem.
as the error indicates the problem is with the select statement at "data_type"
Invalid column name 'DATA_TYPE'
if you check the columns for systables, do you see and column with name DATA_TYPE
check here - http://msdn.microsoft.com/en-us/library/ms186816.aspx
to check if your query runs properly, first execute the select statement in any sql client replacing the variables with values and then use it in the code