OleDbCommandBuilder Class

Definition

public ref class OleDbCommandBuilder sealed : System::Data::Common::DbCommandBuilder

public sealed class OleDbCommandBuilder : System.Data.Common.DbCommandBuilder

type OleDbCommandBuilder = class
    inherit DbCommandBuilder

Public NotInheritable Class OleDbCommandBuilder
Inherits DbCommandBuilder

Inheritance

Object

MarshalByRefObject

Component

DbCommandBuilder

OleDbCommandBuilder

Examples

The following example uses the OleDbCommand, along OleDbDataAdapter and OleDbConnection, to select rows from a data source. The example is passed an initialized DataSet, a connection string, a query string that is an SQL SELECT statement, and a string that is the name of the data source table. The example then creates an OleDbCommandBuilder.

public static DataSet UpdateRows(string connectionString,
    string queryString, string tableName)
{
    DataSet dataSet = new DataSet();
    using (OleDbConnection connection = new OleDbConnection(connectionString))
    {
        OleDbDataAdapter adapter = new OleDbDataAdapter();
        adapter.SelectCommand = new OleDbCommand(queryString, connection);
        OleDbCommandBuilder cb = new OleDbCommandBuilder(adapter);

        connection.Open();

        adapter.Fill(dataSet, tableName);

        //code to modify data in DataSet here

        cb.GetDeleteCommand();
        //Without the OleDbCommandBuilder this line would fail
        adapter.Update(dataSet, tableName);

        connection.Close();
    }
    return dataSet;
}

Public Shared Function UpdateRows(ByVal connectionString As String, _
ByVal queryString As String, ByVal tableName As String) As DataSet

    Dim dataSet As New DataSet()

    Using connection As New OleDbConnection(connectionString)
        Dim adapter As New OleDbDataAdapter()
        adapter.SelectCommand = New OleDbCommand(queryString, connection)
        Dim builder As New OleDbCommandBuilder(adapter)

        connection.Open()

        adapter.Fill(dataSet, tableName)

        ' Code to modify data in DataSet here 

        builder.GetUpdateCommand()

        ' Without the OleDbCommandBuilder this line would fail.
        adapter.Update(dataSet, tableName)
    End Using

    Return dataSet
End Function

Remarks

The OleDbDataAdapter does not automatically generate the SQL statements required to reconcile changes made to a DataSet with the associated data source. However, you can create an OleDbCommandBuilder object to automatically generate SQL statements for single-table updates if you set the SelectCommand property of the OleDbDataAdapter. Then, any additional SQL statements that you do not set are generated by the OleDbCommandBuilder.

The OleDbCommandBuilder registers itself as a listener for RowUpdating events whenever you set the DataAdapter property. You can only associate one OleDbDataAdapter or OleDbCommandBuilder object with each other at one time.

To generate INSERT, UPDATE, or DELETE statements, the OleDbCommandBuilder uses the SelectCommand property to retrieve a required set of metadata automatically. If you change the SelectCommand after the metadata is retrieved, such as after the first update, you should call the RefreshSchema method to update the metadata.

The OleDbCommandBuilder also uses the Connection, CommandTimeout, and Transaction properties referenced by the SelectCommand. The user should call RefreshSchema if one or more of these properties are modified, or if the SelectCommand itself is replaced. Otherwise the InsertCommand, UpdateCommand, and DeleteCommand properties retain their previous values.

If you call Dispose, the OleDbCommandBuilder is disassociated from the OleDbDataAdapter, and the generated commands are no longer used.

See also

• Generating Commands with CommandBuilders