OracleDataAdapter Requery Property

The OracleDataAdapter Requery property controls whether or not queries are reexecuted for OracleDataAdapter Fill calls after the initial Fill call.

The OracleDataAdapter Fill method allows appending or refreshing data in the DataSet. When appending the DataSet using the same query with subsequent Fill calls, reexecuting the query may not be desirable.

When the Requery property is set to true, each subsequent Fill call reexecutes the query and fills the DataSet. This is an expensive operation, and if the reexecution is not required, set Requery to false. If any of the SelectCommand properties or associated parameters must be changed, Requery must be set to true.

When the Requery property is set to false, the DataSet has all the data as a snapshot at a particular time. The query is executed only for the first Fill call; subsequent Fill calls fetch the data from a cursor opened with the first execution of the query. This feature is supported only for forward-only fetches. Fill calls that try to fetch rows before the last fetched row raise an exception. The connection used for the first Fill call must be available for subsequent Fill calls.

When filling a DataSet with an OracleRefCursor object, the Requery property can be used in a similar manner. When the Requery property is set to false, both the connection used for the first Fill call and the OracleRefCursor object must be available for the subsequent Fill calls.