Essential ADO.NET

5.4. How DataAdapter.Fill Works

After understanding what DataAdapter.Fill does in general, programmers invariably ask two questions: “What calls does it make to my data provider?” and, more directly, “What does it call inside my database?” These questions are an attempt to determine the overhead of using DataAdapter.Fill versus getting data through a DataReader, to determine whether to use one provider over another one, or even to determine whether to use a different data access API, such as ADO (classic) through COM interoperability. Because almost every data provider uses the same base classes (DbDataAdapter and DataAdapter in System.Data.Common), it is straightforward to determine which calls are made to the data provider. And because data ...