Question

I am confused about the SQL Data Adapter in ADO.Net.

What is the difference between the below:

SqlDataAdapter adapter = new SqlDataAdapter("Select * from Course", sqlconn);

and

 SqlCommand Command = new SqlCommand("Select * from Course", sqlconn);

Can someone please explain?

Answer 1

The basic answer is: Not a lot in the guts of it.

SQLDataAdapter uses SQLCommand

The main differences are:

1. DataAdapter can populate directly
   into a DataTable, the command
   returns a DataReader
2. DataAdapter can use multiple Commands to support Select, Insert,
   Update and Delete commands

So you would use Command to get a DataReader to iterate once over everything it returns.

You would use DataAdapter to put it all into a DataTable to reuse it, and to support pushing data back to the DB server.