ADO.NET in a Nutshell

Working with Tables in the DataSet

Tables belonging to the DataSet are stored as DataTable objects in a DataTableCollection object and accessed through the Tables property of the DataSet. This section examines some methods and properties of the DataTableCollection.

Tables are added to the DataSet using the Add( ) method of the DataTableCollection. The Add( ) method takes an optional table name argument. If this argument isn’t supplied, the tables are automatically named Table, Table1, and so on. The following example adds a table to a DataSet:

DataSet ds = new DataSet("MyDataSet");

DataTable dt = new DataTable("MyTable");



// ... code to define the schema for the newly constructed DataTable



ds.Tables.Add(dt);

The AddRange( ) method allows more than one table to be added to the DataSet in the same statement. The method takes an array of DataTable objects as the argument, as the following example shows:

// create two new tables

DataTable dt1 = new DataTable();

DataTable dt2 = new DataTable();



// use the AddRange() method to add them to the DataSet.

ds.Tables.AddRange(new DataTable[] {dt1, dt2});

A DataTable can also be created automatically in a DataSet when the Fill( ) or FillSchema( ) method of the DataAdapter is called. A new table is created and filled with the data or schema, respectively, from the data source, as illustrated in the following code:

// connection and select command strings String connString = "Data Source=(local);Integrated security=SSPI;" + "Initial Catalog=Northwind;"; ...