悲观观定SQL Server和Oracle

/*

 author:wuxiuxiang;
Email:imessage@126.com

*/

using System;
using System.Data;
namespace com.cuc.wu.example
{
   public class class1
   {
  //For SQL Server 需要与Connection相关的一个Transaction的隔离级别为
    //Repeatable Read或Serializable,对于Oracle,在Command中使用select for update即可
       public void LockedSQLDataRow()
       {
           DataSet ds = new DataSet();
           SqlConnection sconn = new SqlConnection("server=localhost;uid=sa;pwd=sa;database=pubs");
           sconn.Open();
           SqlTransaction tx = new sconn.BeginTransaction(IsolationLevel.Serializable);

           SqlCommand cmd = new SqlCommand("select * from authors",conn,tx);
           SqlDataAdapter da = new SqlDataAdapter(cmd);
           da.Fill(ds,"autors");
           //rows locked here

           ds.Tables[0].Rows[1][2]="Free";

           SqlCommandBuilder bld = new SqlCommandBuilder(da);
           da.Update(ds,"authors");
           tx.commit();
           //rows unlocked here
           da.Dispose();
           conn.Close();//ÏÔʽÊÍ·Å×ÊÔ´
       }
       public void LockedORADataRow()
       {
           DataSet ds = new DataSet();
           OleDbConnection oconn = new OleDbConnection("provider=msdaora;data source=ocr11;user id=scott;password=tiger");
           conn.Open();

           OleDbTransaction tx = oconn.BeginTransaction();
           OleDbCommand cmd = new OleDbCommand("select * form emp for update ",conn,tx);
           
           OleDbDataAdapter da = new OleDbDataAdapter(cmd);
           da.Fill(ds,"emp");
           //rows locked here;

           ds.Tables[0].Rows[9][2] = "CLERK";
           OleDbCommandBuilder bld = new OleDbCommandBuilder(da);
           da.Update(ds,"emp");
           tx.Commit();
           //rows unlocked here
           da.Dispose();
           oconn.Close();       
       }
   };

}