Sending Query or Stored Procedure Parameters
When the client dataset's CommandType property is ctQuery or ctStoredProc, or, if the client dataset is a TClientDataSet instance, when the associated provider represents the results of a query or stored procedure, you can use the Params property to specify parameter values. When the client dataset requests data from the source dataset or uses its Execute method to run a query or stored procedure that does not return a dataset, it passes these parameter values along with the request for data or the execute command. When the provider receives these parameter values, it assigns them to its associated dataset. It then instructs the dataset to execute its query or stored procedure using these parameter values, and, if the client dataset requested data, begins providing data, starting with the first record in the result set.
Note: Parameter names should match the names of the corresponding parameters on the source dataset.