DeleteCommand Property

SqlDataAdapter.DeleteCommand Property

 

Gets or sets a Transact-SQL statement or stored procedure to delete records from the data set.

Namespace:   System.Data.SqlClient
Assembly:  System.Data (in System.Data.dll)

Public Property DeleteCommand As SqlCommand

Property Value

Type: System.Data.SqlClient.SqlCommand

A SqlCommand used during Update to delete records in the database that correspond to deleted rows in the DataSet.

During Update, if this property is not set and primary key information is present in the DataSet, the DeleteCommand can be generated automatically if you set the SelectCommand property and use the SqlCommandBuilder. Then, any additional commands that you do not set are generated by the SqlCommandBuilder. This generation logic requires key column information to be present in the DataSet. For more information, see Generating Commands with CommandBuilders.

When DeleteCommand is assigned to a previously created SqlCommand, the SqlCommand is not cloned. The DeleteCommand maintains a reference to the previously created SqlCommand object.

For every column that you propagate to the data source on Update, a parameter should be added to the InsertCommand, UpdateCommand, or DeleteCommand. The SourceColumn property of the parameter should be set to the name of the column. This indicates that the value of the parameter is not set manually, but is taken from the particular column in the currently processed row.

The following example creates a SqlDataAdapter and sets the SelectCommand, InsertCommand, UpdateCommand, and DeleteCommand properties. It assumes you have already created a SqlConnection object.

Public Function CreateCustomerAdapter( _
  ByVal connection As SqlConnection) As SqlDataAdapter

    Dim adapter As SqlDataAdapter = New SqlDataAdapter()

    ' Create the SelectCommand.
    Dim command As SqlCommand = New SqlCommand( _
        "SELECT * FROM Customers " & _
        "WHERE Country = @Country AND City = @City", connection)

    ' Add the parameters for the SelectCommand.
    command.Parameters.Add("@Country", SqlDbType.NVarChar, 15)
    command.Parameters.Add("@City", SqlDbType.NVarChar, 15)

    adapter.SelectCommand = command

    ' Create the InsertCommand.
    command = New SqlCommand( _
        "INSERT INTO Customers (CustomerID, CompanyName) " & _
        "VALUES (@CustomerID, @CompanyName)", connection)

    ' Add the parameters for the InsertCommand.
    command.Parameters.Add("@CustomerID", SqlDbType.NChar, 5, "CustomerID")
    command.Parameters.Add("@CompanyName", SqlDbType.NVarChar, 40, "CompanyName")

    adapter.InsertCommand = command

    ' Create the UpdateCommand.
    command = New SqlCommand( _
        "UPDATE Customers SET CustomerID = @CustomerID, CompanyName = @CompanyName " & _
        "WHERE CustomerID = @oldCustomerID", connection)

    ' Add the parameters for the UpdateCommand.
    command.Parameters.Add("@CustomerID", SqlDbType.NChar, 5, "CustomerID")
    command.Parameters.Add("@CompanyName", SqlDbType.NVarChar, 40, "CompanyName")
    Dim parameter As SqlParameter = command.Parameters.Add( _
        "@oldCustomerID", SqlDbType.NChar, 5, "CustomerID")
    parameter.SourceVersion = DataRowVersion.Original

    adapter.UpdateCommand = command

    ' Create the DeleteCommand.
    command = New SqlCommand( _
        "DELETE FROM Customers WHERE CustomerID = @CustomerID", connection)

    ' Add the parameters for the DeleteCommand.
    command.Parameters.Add( _
        "@CustomerID", SqlDbType.NChar, 5, "CustomerID")
    parameter.SourceVersion = DataRowVersion.Original

    adapter.DeleteCommand = command

    Return adapter
End Function

.NET Framework
Available since 1.1
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