Transformations > SQL transformation > Connected or unconnected SQL transformation for stored procedure processing
  

Connected or unconnected SQL transformation for stored procedure processing

When you call a stored procedure in an SQL transformation, you can use a connected or an unconnected SQL transformation.
You process a stored procedure with a connected SQL transformation when you need data from an input field sent as an input parameter to the stored procedure, or you need the results of a stored procedure sent as an output parameter to another transformation.
You process a stored procedure with an unconnected SQL transformation when you need the stored procedure to run before or after a mapping, run nested stored procedures, or call the stored procedure multiple times.
The following table describes when you would use a connected or unconnected SQL transformation to process a stored procedure:
Scenario
SQL transformation type
Run a stored procedure before or after a mapping.
Unconnected
Run a stored procedure once during a mapping.
Unconnected
Run a stored procedure every time a row passes through the SQL transformation.
Connected or unconnected
Run a stored procedure based on data that passes through the mapping such as when a specific field does not contain a null value.
Unconnected
Pass parameters to the stored procedure and receive a single output parameter.
Connected or unconnected
Pass parameters to the stored procedure and receive multiple output parameters.
Note: To get multiple output parameters from an unconnected SQL transformation, you must create variables for each output parameter.
Connected or unconnected
Run nested stored procedures.
Unconnected
Call a stored procedure multiple times within a mapping.
Unconnected