DELETE

The delete operation is used to delete records from a table. A filter must be specified for the operation to take place (or you may end up deleting everything!) 

 

DELETE FROM Customers WHERE State = @State
Deletes all the customer records matching the parameter of State..

Note the following code sample:

Public Sub deleteFromCart(CartID As Integer)

        Dim myConn As SqlConnection = New SqlConnection(MyConnString)
        myConn.Open()
        Dim strSQL As String = "DELETE FROM XYZCart WHERE CartID = @CartID"
        Dim myComm As SqlCommand = New SqlCommand(strSQL, myConn)
        myComm.Parameters.AddWithValue("@CartID", CartID)
        myComm.ExecuteNonQuery()
        myConn.Close()

End Sub

Once again, parameters are used to pass the criteria used to delete the records and the ExecuteNonQuery method of the command object is engaged to complete the operation.

Database Operations

There are four commands that may be executed against database tables:

* SELECT
* INSERT
* DELETE
* UPDATE


Commands are executed using Structured Query Language (SQL).