Delete database records through OleDbCommand and verify the results

   


using System;
using System.Data;
using System.Data.OleDb;

public class ExtractInfo {    
 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 Sales database");
   OleDbCommand cmd = con.CreateCommand();
   
   cmd.CommandText ="DELETE FROM Employee WHERE ID = 01"; 
   cmd.ExecuteNonQuery();
   cmd.CommandText = "SELECT First_Name FROM Employee";
   OleDbDataReader reader = cmd.ExecuteReader();
   Console.WriteLine();
   while(reader.Read()) 
     Console.WriteLine(reader.GetString(0)); 
   reader.Close();

   con.Close();
 }
}
           
          


Between certain dates

   


using System;
using System.Data;
using System.Data.OleDb;

public class ExtractInfo {    
 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 Sales database");
   OleDbCommand cmd = con.CreateCommand();
   
   cmd.CommandText =  "SELECT OrderNumber FROM Orders "
             + "WHERE OrderDate BETWEEN #4/1/99# AND #4/30/99#";
   OleDbDataReader reader = cmd.ExecuteReader();
   Console.WriteLine();
   Console.WriteLine
      ("   Order numbers of orders from 4/1/99 to 4/30/99");
   while(reader.Read())
     Console.WriteLine(reader.GetString(0)); 
   reader.Close();




   con.Close();
 }
}
           
          


Get count value from a select query


   


using System;
using System.Data;
using System.Data.OleDb;

public class DatabaseInfo {    
 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 command = con.CreateCommand();
   command.CommandText = "SELECT COUNT(*) FROM Employee";
   Console.WriteLine("Number of Employee rows: {0}",(int)command.ExecuteScalar());
   con.Close();
 }
}
 
           
          


Get max column value


   

using System;
using System.Data;
using System.Data.OleDb;

public class DatabaseInfo {    
 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 command = con.CreateCommand();
   command.CommandText ="SELECT MAX(Salary) FROM Employee";
   Console.WriteLine("Max of salary: {0:C}",(decimal)command.ExecuteScalar());
   con.Close();
 }
}
 

           
          


Get column average


   


using System;
using System.Data;
using System.Data.OleDb;

public class DatabaseInfo {    
 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 command = con.CreateCommand();
   command.CommandText = "SELECT AVG(Salary) FROM Employee";
   Console.WriteLine("Average of salary: {0:C}",(decimal)command.ExecuteScalar());


   con.Close();
 }
}
 
           
          


Execute aggregate function: sum


   

using System;
using System.Data;
using System.Data.OleDb;

public class DatabaseInfo {    
 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 command = con.CreateCommand();
   command.CommandText ="SELECT SUM(salary) FROM Employee";
   Console.WriteLine("Sum of salary: {0:C}",(decimal)command.ExecuteScalar());


   con.Close();
 }
}
 

           
          


OleDbConnection: ConnectionTimeout

   
 

using System;
using System.Data;
using System.Data.SqlClient;
using System.Data.OleDb;

class MainClass {
    public static void Main() {
        using (OleDbConnection con = new OleDbConnection()) {
            con.ConnectionString = "Provider=SQLOLEDB;" +     
                @"Data Source=.sqlexpress;" + 
                "Initial Catalog=Northwind;" + 
                "Integrated Security=SSPI";    

            con.Open();

            if (con.State == ConnectionState.Open) {
                Console.WriteLine("  Timeout = " + con.ConnectionTimeout);
            } else {
                Console.WriteLine("OleDbConnection failed to open.");
                Console.WriteLine("  Connection State = " + con.State);
            }
        }
    }
}