ADO.NET 3.5 Cookbook, 2nd Edition

5.6. Modifying Data in a Text File

Problem

You need to modify the contents of a text file.

Solution

Use an OLE DB DataAdapter together with parameterized SQL insert and update statements.

The solution uses the text file Category.txt shown in Figure 5-10.

Figure 5-10. Text file Category.txt

The solution creates a DataAdapter and creates parameterized insert and update SQL statements. A DataSet is created and filled from the text file using the DataAdapter. The initial contents are output to the console. Next, a new row is added and the Update() method of the DataAdapter is called to update the text file. The DataSet is reloaded and its contents output to the console. Finally, a row is updated and the Update() method of the DataAdapter is called to update the text file. The DataSet is reloaded and its contents output to the console.

The C# code in Program.cs in the project ModifyTextFileData is shown in Example 5-12.

Example 5-12. File: Program.cs for ModifyTextFileData solution

using System; using System.Data; using System.Data.OleDb; namespace ModifyTextFileData { class Program { static void Main(string[] args) { string oledbConnectString = "Provider=Microsoft.ACE.OLEDB.12.0;" + @"Data Source=..\..\..\;" + "Extended Properties=\"text;HDR=yes;FMT=Delimited\";"; string sqlSelect = "SELECT * FROM [Category.txt]"; // Create the connection OleDbConnection connection = new OleDbConnection(oledbConnectString); ...