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Listing Tables in an Access Database

Problem

You need a list of all tables in your Access database.

Solution

Use the GetOLEDBSchemaTable( ) method of the OleDbConnection class or use ADOX through COM interop.

The first technique uses the GetOLEDBSchemaTable( ) method to return schema information about user tables. These results are then displayed.

For the second technique, youll need a reference to the Primary Interop Assembly (PIA) for ADO provided in the file ADODB.DLL ; select adodb from the .NET tab in Visual Studio .NETs Add Reference Dialog. Youll also need a reference to Microsoft ADO Ext. 2.7 for DDL and Security from the COM tab in Visual Studio .NETs Add Reference Dialog.

The second technique creates an ADOX Catalog object through COM interop. The Tables property of this object accesses the collection of tables from which the name and other information are displayed.

The C# code is shown in Example 10-14.

Example 10-14. File: ListAccessTablesForm.cs
// Namespaces, variables, and constants
using System;
using System.Configuration;
using System.Text;
using System.Data;
using System.Data.OleDb;

// . . .

// OLE DB

StringBuilder result = new StringBuilder( );

// Open the OLE DB connection.
OleDbConnection conn = new OleDbConnection(
 ConfigurationSettings.AppSettings["MsAccess_ConnectString"]);
conn.Open( );

// Retrieve schema information for all tables.
DataTable schemaTable = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables,
 new object[] {null, null, null, "TABLE"});

result.Append("TABLE" + Environment.NewLine);
// Iterate over the collection of table records.
foreach(DataRow row in schemaTable.Rows)
{
 result.Append(row["TABLE_NAME"] + Environment.NewLine);
}

conn.Close( );

resultTextBox.Text = result.ToString( );

// ADOX

StringBuilder result = new StringBuilder( );

// Open the connection.
ADODB.Connection conn = new ADODB.ConnectionClass( );
conn.Open(ConfigurationSettings.AppSettings["MsAccess_ConnectString"],
 "", "", 0);

// Create an ADOX catalog object for the connecton.
ADOX.Catalog cat = new ADOX.Catalog( );
cat.ActiveConnection = conn;

result.Append("TABLE	KEY" + Environment.NewLine);
// Iterate over the collection of tables.
foreach(ADOX.Table table in cat.Tables)
{
 if(table.Type == "TABLE")
 {
 result.Append(table.Name + Environment.NewLine);
 // Iterate over the collection of keys for the table.
 foreach(ADOX.Key key in table.Keys)
 {
 result.Append("	" + key.Name + " (");
 // Iterate over the collection of columns for the key.
 foreach(ADOX.Column col in key.Columns)
 {
 result.Append(col.Name + ", ");
 }
 result.Remove(result.Length - 2, 2).Append(")" +
 Environment.NewLine);
 }
 result.Append(Environment.NewLine);
 }
}

cat = null;
conn.Close( );

resultTextBox.Text = result.ToString( );

Discussion

The solution shows two techniques that you can use to get a list of tables in an Access database.

The first technique uses the GetOleDbSchemaTable( ) method of the OLE DB connection object. This technique is discussed in Recipe 10.2.

The second technique uses ActiveX Database Objects Extensions (ADOX) from COM interop. ADOX has a Tables property that exposes a collection of Table objects in the database. The user tables are determined by iterating over the collection of tables and selecting only those where Type property of the Table is TABLE .

The Table object also exposes collections of Columns , Indexes , Keys , and Properties that can be used to further investigate the database. As an example, the sample code iterates over the collection of Keys in each table to get the list of both primary and foreign keys.

Connecting to Data

Retrieving and Managing Data

Searching and Analyzing Data

Adding and Modifying Data

Copying and Transferring Data

Maintaining Database Integrity

Binding Data to .NET User Interfaces

Working with XML

Optimizing .NET Data Access

Enumerating and Maintaining Database Objects

Appendix A. Converting from C# to VB Syntax





ADO. NET Cookbook
ADO.NET 3.5 Cookbook (Cookbooks (OReilly))
ISBN: 0596101406
EAN: 2147483647
Year: 2002
Pages: 222
Authors: Bill Hamilton
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