Csharp/C Sharp/Database ADO.net/Select Query

Finding Rows In DataSet

<source lang="csharp"> /*

* C# Programmers Pocket Consultant
* Author: Gregory S. MacBeth
* Email: gmacbeth@comporium.net
* Create Date: June 27, 2003
* Last Modified Date:
* Version: 1
*/

using System; using System.Data; using System.Data.SqlClient; namespace Client.Chapter_13___ADO.NET {

   public class FindingRowsInData
   {
       public static void Main()
       {
           SqlConnection MyConnection = new SqlConnection(@"Data Source=(local); Initial Catalog = CaseManager; Integrated Security=true");
           SqlDataAdapter MyDataAdapter = new SqlDataAdapter("SELECT * FROM Test", MyConnection);
           SqlCommandBuilder MyCmd = new SqlCommandBuilder(MyDataAdapter);
           DataSet MyDataSet = new DataSet();
           MyDataAdapter.Fill(MyDataSet);
           DataColumn[] MyKey = new DataColumn[1];
           MyKey[0] = MyDataSet.Tables[0].Columns[0];
           MyDataSet.Tables[0].PrimaryKey = MyKey;
           DataRow FindMyRow = MyDataSet.Tables[0].Rows.Find(1);
       }
   }

}

      </source>

illustrates how to perform a SELECT statement using ADO.NET

<source lang="csharp"> /* 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.rumandText = 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();
 }

}

      </source>