Csharp/C Sharp by API/System.Data.OleDb/OleDbCommand

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new OleDbCommand(String SQL)

<source lang="csharp"> using System; using System.Data; using System.Data.OleDb; class MainClass {

 [STAThread]
 static void Main(string[] args)
 {
   string ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=c:\\Northwind.mdb";
   string SQL = "SELECT * FROM Orders";
   OleDbConnection conn = new OleDbConnection(ConnectionString);
   OleDbCommand cmd = new OleDbCommand(SQL);
   cmd.Connection = conn;
   conn.Open();
   OleDbDataReader reader = cmd.ExecuteReader();
   while (reader.Read()) 
   {
     Console.Write("OrderID:"+reader.GetInt32(0).ToString() );
     Console.Write(" ,");
     Console.WriteLine("Customer:" + reader.GetString(1).ToString() );
   }
   reader.Close();
   conn.Close();
 }

}


 </source>


OleDbCommand.ExecuteNonQuery()

<source lang="csharp">

using System; using System.Data; using System.Data.OleDb; using System.Data.SqlClient; class MainClass {

 static void Main(string[] args)
   {
       string ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0; Data Source=c:\Northwind.mdb";
       OleDbConnection conn = new OleDbConnection(ConnectionString);
   conn.Open();
   OleDbCommand cmd = new OleDbCommand("Customers", conn);
   cmd.rumandText = @"DELETE * FROM Customers";
   cmd.ExecuteNonQuery();
         
       conn.Close();                  
   }

}


 </source>


OleDbCommand.ExecuteReader

<source lang="csharp"> using System; using System.Data; using System.Data.rumon; using System.Data.OleDb; class MainClass {

 static void Main(string[] args)
 {
   string connectionString = "Provider=Microsoft.JET.OLEDB.4.0;data source=C:\\Northwind.mdb";
   OleDbConnection conn = new OleDbConnection(connectionString);
   string sql = "SELECT * FROM Orders";
                                         
   OleDbCommand cmd = new OleDbCommand(sql, conn);
   conn.Open();
   OleDbDataReader reader;
   reader = cmd.ExecuteReader();
   while (reader.Read()) 
   {
     Console.Write(reader.GetString(0).ToString() + " ," );
     Console.Write(reader.GetString(1).ToString() + " ," );
     Console.WriteLine("");
   }
   reader.Close();
   conn.Close();
 }

}


 </source>


OleDbCommand.ExecuteScalar

<source lang="csharp"> using System; using System.Data; using System.Data.OleDb; using System.Data.SqlClient; class MainClass {

   static void Main(string[] args)
   {
       string ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0; Data Source=c:\Northwind.mdb";
       OleDbConnection conn = new OleDbConnection(ConnectionString);
       conn.Open();
       OleDbCommand cmd = new OleDbCommand();
       cmd.rumandText = "SELECT Count(*) FROM Customers";
       cmd.Connection = conn;
       int counter = (int)cmd.ExecuteScalar();
       
       Console.WriteLine("Total rows returned are :" + counter.ToString());
              
       conn.Close();                  
   }

}


 </source>


OleDbCommand.Transaction

<source lang="csharp"> using System; using System.Data; using System.Data.OleDb; public class Transact {

public static void Main () { 
  String connect = "Provider=Microsoft.JET.OLEDB.4.0;data source=.\\Employee.mdb";
  OleDbConnection con = new OleDbConnection(connect);
  con.Open();  
  Console.WriteLine("Made the connection to the database");
  OleDbCommand cmd = con.CreateCommand();
  OleDbTransaction trans = con.BeginTransaction();
  cmd.Transaction = trans;
  cmd.rumandText ="INSERT INTO Employee VALUES (09,"qwe","ewq",123)";
  cmd.ExecuteNonQuery();
  cmd.rumandText = "SELECT First_name FROM Employee";
  OleDbDataReader reader = cmd.ExecuteReader();
  while(reader.Read()) 
    Console.WriteLine("{0}",
              reader.GetString(0));
  reader.Close();
  con.Close();
}

}

 </source>