SqlHelper 数据库操作类2

 

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

namespace  lsb.DBUtility
{
     ///   <summary>
     ///  SQL Server 数据库操作类
     ///   </summary>
     public   class  SqlHelper
    {
         private   static   string  connectionString  =   " Data Source=.;Initial Catalog=FBMS;Integrated Security=True " ;

         ///   <summary>
         ///  执行查询, 返回单个值
         ///   </summary>
         public   static   object  ExecuteScalar( string  sql)
        {
             using  (SqlConnection conn  =   new  SqlConnection(connectionString))
            {
                 using  (SqlCommand cmd  =   new  SqlCommand(sql, conn))
                {
                     try
                    {
                        conn.Open();
                         return  cmd.ExecuteScalar();
                    }
                     catch
                    {
                         throw ;
                    }
                }
            }
        }

         ///   <summary>
         ///  执行带参数查询, 返回单个值
         ///   </summary>
         public   static   object  ExecuteScalar( string  sql, SqlParameter[] cmdParms)
        {
             using  (SqlConnection conn  =   new  SqlConnection(connectionString))
            {
                 using  (SqlCommand cmd  =   new  SqlCommand())
                {
                     try
                    {
                        PrepareCommand(cmd, conn,  null , sql, cmdParms);
                         object  obj  =  cmd.ExecuteScalar();
                        cmd.Parameters.Clear();
                         return  obj;
                    }
                     catch
                    {
                         throw ;
                    }
                }
            }
        }

         ///   <summary>
         ///  执行查询, 返回多个值
         ///   </summary>
         public   static  SqlDataReader ExecuteReader( string  sql)
        {
             using  (SqlConnection conn  =   new  SqlConnection(connectionString))
            {
                 using  (SqlCommand cmd  =   new  SqlCommand(sql, conn))
                {
                     try
                    {
                        conn.Open();
                         return  cmd.ExecuteReader();
                    }
                     catch
                    {
                         throw ;
                    }
                }
            }
        }

         ///   <summary>
         ///  执行带参数查询, 返回多个值
         ///   </summary>
         public   static  SqlDataReader ExecuteReader( string  sql, SqlParameter[] cmdParms)
        {
             using  (SqlConnection conn  =   new  SqlConnection(connectionString))
            {
                 using  (SqlCommand cmd  =   new  SqlCommand())
                {
                     try
                    {
                        PrepareCommand(cmd, conn,  null , sql, cmdParms);
                        SqlDataReader sdr  =  cmd.ExecuteReader();
                        cmd.Parameters.Clear();
                         return  sdr;
                    }
                     catch
                    {
                         throw ;
                    }
                }
            }
        }

         ///   <summary>
         ///  执行非查询, 返回影响行数
         ///   </summary>
         public   static   int  ExceuteNonQuery( string  sql,  params  SqlParameter[] cmdParms)
        {
             using  (SqlConnection conn  =   new  SqlConnection(connectionString))
            {
                 using  (SqlCommand cmd  =   new  SqlCommand())
                {
                     try
                    {
                        PrepareCommand(cmd, conn,  null , sql, cmdParms);
                         int  rows  =  cmd.ExecuteNonQuery();
                        cmd.Parameters.Clear();
                         return  rows;
                    }
                     catch
                    {
                         throw ;
                    }
                }
            }
        }

         ///   <summary>
         ///  
         ///   </summary>
         ///   <param name="cmd"></param>
         ///   <param name="conn"></param>
         ///   <param name="trans"></param>
         ///   <param name="cmdText"></param>
         ///   <param name="cmdParms"></param>
         private   static   void  PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans,  string  cmdText, SqlParameter[] cmdParms)
        {
             if  ((conn.State  ==  ConnectionState.Broken)  ||  (conn.State  ==  ConnectionState.Closed))
            {
                conn.Open();
            }

            cmd.Connection  =  conn;
            cmd.CommandText  =  cmdText;

             if  (trans  !=   null )
                cmd.Transaction  =  trans;

            cmd.CommandType  =  CommandType.Text;

             if  (cmdParms  !=   null )
            {
                 foreach  (SqlParameter parm  in  cmdParms)
                {
                     if  ((parm.Direction  ==  ParameterDirection.InputOutput  ||  parm.Direction  ==  ParameterDirection.Input)  &&  (parm.Value  ==   null ))
                    {
                        parm.Value  =  DBNull.Value;
                    }
                    cmd.Parameters.Add(parm);
                }
            }
        }
    }
}