ADO.NET Cookbook

4.6. Adding Records with a GUID Primary Key

Problem

You want to add records to a DataTable that uses a GUID as its primary key and has related child records.

Solution

Use the DataTable.RowChanging event handler.

The sample code contains three event handlers:

Form.Load

Sets up the sample by creating a DataSet containing two tables, a parent and child, both having a GUID primary key column with the DefaultValue set to a new GUID. A relation based on the parent table GUID and a foreign key GUID in the child table is added to the DataSet. The default view of the parent table is bound to the data grid on the form. Event handlers are added for the RowChanging event in both the parent and child DataTable objects.

Parent DataTable.RowChanging

Sets the default value of the primary key column in the parent table to a new GUID value when a new row has been added to the parent table.

Child DataTable.RowChanging

Sets the default value of the primary key column in the child table to a new GUID value when a new row has been added to the child table.

The C# code is shown in Example 4-9.

Example 4-9. File: AddGuidPKRecordForm.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 ...