Obtaining a Single Value from a Database
You may need to return database information that is simply a single value rather than in the form of a table or data stream. For example, you may want to return the result of an aggregate function such as Count(*), Sum(Price), or Avg(Quantity). The Command object provides the capability to return single values using the ExecuteScalar method. The ExecuteScalar method returns as a scalar value the value of the first column of the first row of the result set.
The following code example returns the number of records in a table using the Count aggregate function.
Dim ordersCMD As SqlCommand = New SqlCommand("SELECT Count(*) FROM Orders", nwindConn) Dim count As Int32 = CInt(ordersCMD.ExecuteScalar()) [C#]SqlCommand ordersCMD = new SqlCommand("SELECT Count(*) FROM Orders", nwindConn); Int32 count = (Int32)ordersCMD.ExecuteScalar();