ADO.NET Cookbook

4.5. Adding Parent/Child Rows with Auto-Incrementing Keys

Problem

You want to insert related parent/child rows into a DataSet where the primary key of the parent table is an automatically incrementing value.

Solution

Use the DataColumn object’s AutoIncrementSeed and AutoIncrementStep properties.

The sample code contains two event handlers:

Form.Load

Sets up the example by creating a DataSet containing a parent and child table. Each table has an AutoIncrement column that is the primary key and has both a seed and step value of -1. A relation is created between the parent and child table. The default view of the parent table is bound to the data grid on the form.

Add Record Button.Click

Adds a new row to the parent table along with a random number of rows to the child table.

The C# code is shown in Example 4-8.

Example 4-8. File: AddParentChildAutoIncrementForm.cs

// Namespaces, variables, and constants using System; using System.Data; using System.Data.SqlClient; // Table name constants private const String PARENTTABLENAME = "ParentTable"; private const String CHILDTABLENAME = "ChildTable"; // Table column name constants for Parent table private const String PARENTID_FIELD = "ParentId"; private const String FIELD1_FIELD = "Field1"; private const String FIELD2_FIELD = "Field2"; // Table column parameter name constants for Parent table private const String CHILDID_FIELD = "ChildId"; private const String FIELD3_FIELD = "Field3"; private const String FIELD4_FIELD = "Field4"; private DataSet ...