NGWS SDK Documentation  

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ADODataSetCommand Class

Represents a set of data commands and a database connection which are used to fill the DataSet and update the data source. At any time, the object refers to only a single record within the current data set.

Object
   Component
      DataSetCommand
         DBDataSetCommand
            ADODataSetCommand

[Visual Basic]
Public Class ADODataSetCommand
   Inherits DBDataSetCommand
[C#]
public class ADODataSetCommand : DBDataSetCommand
[C++]
public __gc class ADODataSetCommand : public DBDataSetCommand
[JScript]
public class ADODataSetCommand extends DBDataSetCommand

Remarks

In the past, data processing has been primarily connection-based. Now, in an effort to make multi-tiered applications more efficient, data processing is turning to a message-based approach that revolves around chunks of information. At the center of this approach is the ADODataSetCommand, which provides a bridge to retrieve and save data between a DataSet and its source data store. The ADODataSetCommand provides this bridge by mapping FillDataSet, which changes the data in the DataSet to match the data in the data source, and Update, which changes the data in the data source to match the data in the DataSet, requests to the appropriate SQL commands against the data store.

If you are connecting to a Microsoft SQL Server database, you may wish to increase your overall performance by using the SQLDataSetCommand along with its associated SQLCommand and SQLConnection.

Useful properties include: SelectCommand, InsertCommand, DeleteCommand, UpdateCommand, and TableMappings.

When you create an instance of ADODataSetCommand, the read/write properties are set to initial values. For a list of these values, see the ADODataSetCommand constructor.

Requirements

Namespace: System.Data.ADO

Assembly: System.Data.dll

Example [C#]

The following example uses the ADOCommand, along ADODataSetCommand and ADOConnection, to select records from an Access data source. The DataSet is then used to insert new records in a SQL Server data source. This example can be modified to migrate an Access database to a SQL Server database.

[C#]

private DataSet InitializeMyDataSet() {
   // creates the table and its columns for the DataSet
   DataSet newData = new DataSet();
   DataTable newTable = newData.Tables.Add("Catagories");

   // add Columns to table
   newTable.Columns.Add("CategoryID",typeof(Int32));
   newTable.Columns.Add("CategoryName", typeof(String));
   newTable.Columns.Add("Description", typeof(String));
   newTable.Columns.Add("Picture",typeof(Byte[]));
   return newData;
}

public void AccessToSQLServer() {
   // set Access connection and select strings
   const string strAccessConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=NWIND_RW.MDB";
   const string strAccessSelect = "SELECT * FROM Categories ORDER BY CategoryID";
   // set SQL Server connection and insert strings
   const string strSQLServerConn = "Data Source=VBsql7;Initial Catalog=Northwind;User ID=sa;Password=;";
   const string strSQLServerInsert = "INSERT INTO Categories(CategoryName, Description, Picture) Values(@CategoryName,@Description,@Picture)";
   // create my DataSet
   DataSet myDataSet = InitializeMyDataSet();
   // create my Access objects
   ADOConnection myAccessConn = new ADOConnection(strAccessConn);
   ADODataSetCommand myAccessDataSetCmd = new ADODataSetCommand();
   myAccessDataSetCmd.SelectCommand = new ADOCommand(strAccessSelect,myAccessConn);
   // create my SQL Server objects
   SQLConnection mySQLConn = new SQLConnection(strSQLServerConn);
   SQLDataSetCommand mySQLDataSetCmd = new SQLDataSetCommand();
   mySQLDataSetCmd.InsertCommand = new SQLCommand(strSQLServerInsert,mySQLConn);
   // fill myDataSet with data from Access
   myAccessConn.Open();
   try {
      myAccessDataSetCmd.FillDataSet(myDataSet,"table");
   }
   finally {
      myAccessConn.Close();
   }

   // update SQL Server with data from the DataSet
   mySQLConn.Open();
   try {
      mySQLDataSetCmd.InsertCommand.Parameters.Add("CategoryName", typeof(String));
      mySQLDataSetCmd.InsertCommand.Parameters.Add("Description", typeof(String));
      mySQLDataSetCmd.InsertCommand.Parameters.Add("Picture", typeof(Byte[]));
      mySQLDataSetCmd.InsertCommand.Parameters[0].SourceColumn = "CategoryName";
      mySQLDataSetCmd.InsertCommand.Parameters[1].SourceColumn = "Description";
      mySQLDataSetCmd.InsertCommand.Parameters[2].SourceColumn = "Picture";
      mySQLDataSetCmd.Update(myDataSet,"table");
   }
   finally {
      mySQLConn.Close();
   }
}

See Also

ADODataSetCommand Members | System.Data.ADO Namespace | ADOConnection | ADOCommand | DataSet | DataTable