Database ADO.net

Oracle connection string for C#

Posted on by coder 
   
 

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

class OleDbConnectionOracle
{
  public static void Main()
  {
    string connectionString = "provider=MSDAORA;data source=ORCL;user id=SCOTT;password=TIGER";
    OleDbConnection myOleDbConnection = new OleDbConnection(connectionString);

    OleDbCommand myOleDbCommand = myOleDbConnection.CreateCommand();

    myOleDbCommand.CommandText = "SELECT empno, ename, sal FROM emp WHERE empno = 7369";

    myOleDbConnection.Open();

    OleDbDataReader myOleDbDataReader = myOleDbCommand.ExecuteReader();

    myOleDbDataReader.Read();

    Console.WriteLine("myOleDbDataReader[" empno"] = " + myOleDbDataReader["empno"]);
    Console.WriteLine("myOleDbDataReader[" ename"] = " + myOleDbDataReader["ename"]);
    Console.WriteLine("myOleDbDataReader[" sal"] = " + myOleDbDataReader["sal"]);

    myOleDbDataReader.Close();
    myOleDbConnection.Close();
  }
}

How to use an OleDbConnection object to connect to an Oracle database

Posted on by coder 
   
 

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

class OleDbConnectionOracle
{
  public static void Main()
  {
    string connectionString = "provider=MSDAORA;data source=ORCL;user id=SCOTT;password=TIGER";
    OleDbConnection myOleDbConnection = new OleDbConnection(connectionString);

    OleDbCommand myOleDbCommand = myOleDbConnection.CreateCommand();

    myOleDbCommand.CommandText = "SELECT empno, ename, sal FROM emp WHERE empno = 7369";

    myOleDbConnection.Open();

    OleDbDataReader myOleDbDataReader = myOleDbCommand.ExecuteReader();

    myOleDbDataReader.Read();

    Console.WriteLine("myOleDbDataReader[" empno"] = " + myOleDbDataReader["empno"]);
    Console.WriteLine("myOleDbDataReader[" ename"] = " + myOleDbDataReader["ename"]);
    Console.WriteLine("myOleDbDataReader[" sal"] = " + myOleDbDataReader["sal"]);

    myOleDbDataReader.Close();
    myOleDbConnection.Close();
  }
}

Committed insert

Posted on by coder 
   


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.CommandText ="INSERT INTO Employee VALUES (12,'CD','wwe',10)";
   cmd.ExecuteNonQuery();
   trans.Commit();


   cmd.CommandText = "SELECT First_name FROM Employee";
   OleDbDataReader reader = cmd.ExecuteReader();

   while(reader.Read()) 
     Console.WriteLine("{0}",
               reader.GetString(0));
   reader.Close();


   con.Close();
 }
}

OleDbTransaction rollback

Posted on by coder 


   


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.CommandText ="INSERT INTO Employee VALUES (09,'qwe','ewq',123)";
   cmd.ExecuteNonQuery();

   cmd.CommandText = "SELECT First_name FROM Employee";
   OleDbDataReader reader = cmd.ExecuteReader();

   while(reader.Read()) 
     Console.WriteLine("{0}",
               reader.GetString(0));
   reader.Close();

   trans.Rollback(); 
 
   cmd.CommandText = "SELECT First_name FROM Employee";
   reader = cmd.ExecuteReader();
   Console.WriteLine("Rolled back insert and update -- table unchanged");
   Console.WriteLine("First_name");
   while(reader.Read()) 
     Console.WriteLine("{0}",
               reader.GetString(0));
   reader.Close();


   con.Close();
 }
}

Use OleDbTransaction

Posted on by coder 


   


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.CommandText = "UPDATE Employee SET Salary = 1342 "
                        + "WHERE ID > 1";
   cmd.ExecuteNonQuery();

   cmd.CommandText = "SELECT First_name FROM Employee";
   OleDbDataReader reader = cmd.ExecuteReader();

   while(reader.Read()) 
     Console.WriteLine("{0}",
               reader.GetString(0));
   reader.Close();

   con.Close();
 }
}

Illustrates transaction processing

Posted on by coder 


   


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.CommandText ="INSERT INTO Employee VALUES (09,'qwe','ewq',123)";
   cmd.ExecuteNonQuery();

   cmd.CommandText = "SELECT First_name FROM Employee";
   OleDbDataReader reader = cmd.ExecuteReader();

   while(reader.Read()) 
     Console.WriteLine("{0}",
               reader.GetString(0));
   reader.Close();

   con.Close();
 }
}

Read query result from OleDbReader

Posted on by coder 
   


using System;
using System.Data.OleDb;

public class ReadFromOleDb
{
  [STAThread]
  static void Main(string[] args)
  {
    String sConn = "provider=sqloledb;server=(local)SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI";
    
    String sSQL = "select id, firstname, lastname from Employee";

    OleDbConnection oConn = new OleDbConnection(sConn);
    oConn.Open();

    OleDbCommand oCmd = new OleDbCommand(sSQL, oConn);
    OleDbDataReader oReader = oCmd.ExecuteReader();

    int idxID = oReader.GetOrdinal("id");
    int idxFirstName = oReader.GetOrdinal("firstname");
    int idxLastName = oReader.GetOrdinal("lastname");

    while(oReader.Read()) {
      Console.WriteLine("{0} {1} {2}",
        oReader.GetValue(idxID),
        oReader.GetValue(idxFirstName),
        oReader.GetValue(idxLastName));
    }
  }
}