using System;
using System.Collections.Generic;
using System.Collections;
using System.Collections.Specialized;
using System.Runtime.Remoting.Messaging;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using System.Text;


public abstract class DBUtility
 {
  //数据库连接字符串
  protected static string connectionstring =  ConfigurationSettings.AppSettings["conStr"];

  public static string conStr
  {
      get
      {
          return connectionstring;
      }
  }

  public DBUtility()
  {
   //
   // todo: 在此处添加构造函数逻辑
   //
  }

  /// <summary>
  /// 执行sql语句，返回影响的记录数
  /// </summary>
  /// <param name="sqlstring"></param>
  /// <returns></returns>
  public static int ExecuteSql(string sqlString)
  {
   using ( SqlConnection connection = new SqlConnection(connectionstring))
   {    
    using (SqlCommand cmd = new SqlCommand(sqlString, connection))
    {
     try
     {  
        connection.Open();
        int rows=cmd.ExecuteNonQuery();
        return rows;
     }
     catch(System.Data.SqlClient.SqlException e)
     {    
        throw new Exception(e.Message);
     }
    }    
   }
  }
  /// <summary>
  /// 执行两条sql语句，实现数据库事务。
  /// </summary>
  /// <param name="sqlstring1"></param>
  /// <param name="sqlstring2"></param>
  public static void ExecuteSqlTran(string sqlstring1,string sqlstring2)
  {
   using (SqlConnection connection = new SqlConnection(connectionstring))
   {
    connection.Open();
    SqlCommand cmd = new SqlCommand();
    cmd.Connection=connection;    
    SqlTransaction tx=connection.BeginTransaction();   
    cmd.Transaction=tx;    
    try
    {     
     cmd.CommandText=sqlstring1;
     cmd.ExecuteNonQuery();
     cmd.CommandText=sqlstring2;
     cmd.ExecuteNonQuery();     
     tx.Commit();     
    }
    catch(System.Data.SqlClient.SqlException e)
    {  
     tx.Rollback();
     throw new Exception(e.Message);
    }
    finally
    {
     cmd.Dispose();
     connection.Close();
    } 
   }
  } 
  /// <summary>
  /// 执行多条sql语句，实现数据库事务，每条语句以“;”分割。
  /// </summary>
  /// <param name="sqlstringlist"></param>
  public static void ExecuteSqlTran(string sqlstringlist)
  {
   using (SqlConnection conn = new SqlConnection(connectionstring))
   {

    conn.Open();
    SqlCommand cmd = new SqlCommand();
    cmd.Connection=conn;    
    SqlTransaction tr =conn.BeginTransaction();   
    cmd.Transaction=tr;    
    try
    {   
     string [] split= sqlstringlist.Split(new char [] {';'});
     foreach (string strsql in split) 
     {
      if (strsql.Trim()!="")
      {
       cmd.CommandText=strsql;
       cmd.ExecuteNonQuery();
      }
     }       
     tr.Commit();     
    }
    catch(System.Data.SqlClient.SqlException e)
    {  
     tr.Rollback();
     throw new Exception(e.Message);
    }
   }
  }
   /// <summary>
  /// 向数据库里插入图像格式的字段
  /// </summary>
  /// <param name="strsql"></param>
  /// <param name="fs"></param>
  /// <returns></returns>
  public static int ExecuteSqlInsertImg(string strsql,byte[] fs)
  {  
   using (SqlConnection connection = new SqlConnection(connectionstring))
   {
    SqlCommand cmd = new SqlCommand(strsql,connection); 
    System.Data.SqlClient.SqlParameter  myparameter = new System.Data.SqlClient.SqlParameter ( "@fs", SqlDbType.Image);
    myparameter.Value = fs ;
    cmd.Parameters.Add(myparameter);
    try
    {
     connection.Open();
     int rows=cmd.ExecuteNonQuery();
     return rows;
    }
    catch(System.Data.SqlClient.SqlException e)
    {    
     throw new Exception(e.Message);
    }
    finally
    {