SqlHelper类

来源：pcdog 作者：佚名出处：巧巧读书 2008-03-27 进入讨论组

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          ''' <summary>
          '''
          ''' </summary>

          ''' <param name="connectionString"></param>
          ''' <param name="cmdType"></param>
          ''' <param name="cmdText"></param>
          ''' <param name="commandParameters">ParamArray 表示函数参数个数不确定C#中为params</param>
          ''' <returns></returns>
          ''' <remarks></remarks>
          Public Shared Function ExecuteReader(ByVal connectionString As String, ByVal cmdType As CommandType, ByVal cmdText As String, ByVal ParamArray commandParameters As SqlParameter()) As SqlDataReader
          Dim cmd As SqlCommand = New SqlCommand
              Dim conn As SqlConnection = New SqlConnection(connectionString)
              Try
                  PrepareCommand(cmd, conn, Nothing, cmdType, cmdText, commandParameters)
                  Dim rdr As SqlDataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection)
                  cmd.Parameters.Clear()
                  Return rdr
              Catch ex As Exception
                  conn.Close()
                  Throw
              End Try
          End Function
          ''' <summary>
          '''
          ''' </summary>
          ''' <param name="connectionString"></param>
          ''' <param name="cmdType"></param>
          ''' <param name="cmdText"></param>
          ''' <param name="commandParameters">ParamArray 表示函数参数个数不确定C#中为params</param>
          ''' <returns></returns>
          ''' <remarks></remarks>
          Public Shared Function ExecuteScalar(ByVal connectionString As String, ByVal cmdType As CommandType, ByVal cmdText As String, ByVal ParamArray commandParameters As SqlParameter()) As Object
              Dim cmd As SqlCommand = New SqlCommand
              Using connection As SqlConnection = New SqlConnection(connectionString)
                  PrepareCommand(cmd, connection, Nothing, cmdType, cmdText, commandParameters)
                  Dim val As Object = cmd.ExecuteScalar()
                  cmd.Parameters.Clear()
                  Return val

           End Using
          End Function
          ''' <summary>
          '''
          ''' </summary>
          ''' <param name="connection"></param>
          ''' <param name="cmdType"></param>
          ''' <param name="cmdText"></param>
          ''' <param name="commandParameters">ParamArray 表示函数参数个数不确定C#中为params</param>
          ''' <returns></returns>
          ''' <remarks></remarks>
          Public Shared Function ExecuteScalar(ByVal connection As SqlConnection, ByVal cmdType As CommandType, ByVal cmdText As String, ByVal ParamArray commandParameters As SqlParameter()) As Object
              Dim cmd As SqlCommand = New SqlCommand
              PrepareCommand(cmd, connection, Nothing, cmdType, cmdText, commandParameters)
              Dim val As Object = cmd.ExecuteScalar()
              cmd.Parameters.Clear()
              Return val
          End Function
          ''' <summary>
          ''' add parameter array to the cache
          ''' </summary>
          ''' <param name="cacheKey"></param>
          ''' <param name="commandParameters">an array of SqlParamters to be cached</param>
          ''' <remarks></remarks>
          Public Shared Sub CacheParameters(ByVal cacheKey As String, ByVal ParamArray commandParameters As SqlParameter())
              parmCache(cacheKey) = commandParameters
          End Sub