Mega Code Archive
Illustrates how to perform a SELECT statement using ADO NET
<![CDATA[
/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy
Publisher: Sybex;
ISBN: 0782129110
*/
/*
Example23_1.cs illustrates how to perform a SELECT statement
using ADO.NET
*/
using System;
using System.Data;
using System.Data.SqlClient;
public class Example23_1
{
public static void Main()
{
// step 1: formulate a string containing the details of the
// database connection
string connectionString =
"server=localhost;database=Northwind;uid=sa;pwd=sa";
// step 2: create a SqlConnection object to connect to the
// database, passing the connection string to the constructor
SqlConnection mySqlConnection =
new SqlConnection(connectionString);
// step 3: formulate a SELECT statement to retrieve the
// CustomerID, CompanyName, ContactName, and Address
// columns for the first ten rows from the Customers table
string selectString =
"SELECT CustomerID, CompanyName, ContactName, Address " +
"FROM Customers " +
"WHERE CustomerID < 'BSBEV'";
// step 4: create a SqlCommand object to hold the SELECT statement
SqlCommand mySqlCommand = mySqlConnection.CreateCommand();
// step 5: set the CommandText property of the SqlCommand object to
// the SELECT string
mySqlCommand.CommandText = selectString;
// step 6: create a SqlDataAdapter object
SqlDataAdapter mySqlDataAdapter = new SqlDataAdapter();
// step 7: set the SelectCommand property of the SqlAdapter object
// to the SqlCommand object
mySqlDataAdapter.SelectCommand = mySqlCommand;
// step 8: create a DataSet object to store the results of
// the SELECT statement
DataSet myDataSet = new DataSet();
// step 9: open the database connection using the
// Open() method of the SqlConnection object
mySqlConnection.Open();
// step 10: use the Fill() method of the SqlDataAdapter object to
// retrieve the rows from the table, storing the rows locally
// in a DataTable of the DataSet object
Console.WriteLine("Retrieving rows from the Customers table");
string dataTableName = "Customers";
mySqlDataAdapter.Fill(myDataSet, dataTableName);
// step 11: get the DataTable object from the DataSet object
DataTable myDataTable = myDataSet.Tables[dataTableName];
// step 12: display the columns for each row in the DataTable,
// using a DataRow object to access each row in the DataTable
foreach (DataRow myDataRow in myDataTable.Rows)
{
Console.WriteLine("CustomerID = " + myDataRow["CustomerID"]);
Console.WriteLine("CompanyName = " + myDataRow["CompanyName"]);
Console.WriteLine("ContactName = " + myDataRow["ContactName"]);
Console.WriteLine("Address = " + myDataRow["Address"]);
}
// step 13: close the database connection using the Close() method
// of the SqlConnection object created in Step 2
mySqlConnection.Close();
}
}
]]>