In a win form I have three consecutive queries, each from a different business object.
Prior to executing the queries I have gathered some criteria from the UI. Due to this I retrieve data using parameterized queries.
Within each query, which is dynamic, is a base or minimum query that executes in case there are no criteria from the UI.
As an argument to each of the queries I give a string containing all the extra criteria that is going into the query and the IDbDataParameter[] with the SqlParameters.

Since each query is going to use the same criteria i thought that I could just call each query with the same criteria string and IDbDataParameter[]. But when executing the second query I receive the following System.ArgumentException from the SQLServer (I guess?) : "The SqlParameter with ParameterName '@address' is already contained by another SqlParameterCollection."
The error occurs when the parameters of the IDbDataParameter[] is added to the DataCommand.Parameters SqlParameterCollection. What I don't get is why these parameters are still there after I have successfully received a result from the first query, from the first business object. And when is this SqlParameterCollection emptied?

All help is welcomed.


Best regards

Filip