使用Directcast从SqlDataSource提取行是否会导致再次访问SQL Server？

Question

I was looking for a way to extract data from a SqlDataSource object within VB.NET code but looking at the code I found for this leads me to believe that the select statement is executed once again during the DirectCast .

Does anyone know if this usage causes an additional select statement to be run even though the SqlDataSource has already run previously?

The post I got this from is here: How can i iterate through row of particular table associated with SqlDataSource control in VS 2008?

Here is the code:

Dim datareader = DirectCast(SqlDataSource2.[Select](DataSourceSelectArguments.Empty), SqlDataReader)

While datareader.Read()        
     Label2.Text = datareader("LastName").ToString()
End While
datareader.Close()

Answer 1

A data reader will read from the source.

If the source is a database, then the reader will read from the database every time you call Read() .

It is unclear to me what your DirectCast is there for or why you are using it.