Imports System.Data
Imports System.Data.SqlClient
Imports System.Configuration
Imports System.Collections
Public MustInherit Class SqlHelper
          ''' <summary>
          ''' 哈希表：缓存参数
          ''' </summary>
          ''' <remarks></remarks>
          Public Shared parmCache As Hashtable = Hashtable.Synchronized(New Hashtable())
          ''' <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 ExecuteNonquery(ByVal connectionString As String, ByVal cmdType As CommandType, ByVal cmdText As String, ByVal ParamArray commandParameters As SqlParameter()) As Int32
              Dim cmd As SqlCommand = New SqlCommand
              Using conn As SqlConnection = New SqlConnection(connectionString)
                  PrepareCommand(cmd, conn, Nothing, cmdType, cmdText, commandParameters)
                  Dim val As Int32 = cmd.ExecuteNonQuery()
                  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 ExecuteNonQuery(ByVal connection As SqlConnection, ByVal cmdType As CommandType, ByVal cmdText As String, ByVal ParamArray commandParameters As SqlParameter()) As Int32
              Dim cmd As SqlCommand = New SqlCommand
              PrepareCommand(cmd, connection, Nothing, cmdType, cmdText, commandParameters)
              Dim val As Int32 = cmd.ExecuteNonQuery()
              cmd.Parameters.Clear()
              Return val
          End Function
          ''' <summary>
          '''
          ''' </summary>
          ''' <param name="trans"></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 ExecuteNonQuery(ByVal trans As SqlTransaction, ByVal cmdType As CommandType, ByVal cmdText As String, ByVal ParamArray commandParameters As SqlParameter()) As Int32
              Dim cmd As SqlCommand = New SqlCommand
              PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, commandParameters)
              Dim val As Int32 = cmd.ExecuteNonQuery()
              cmd.Parameters.Clear()
              Return val
          End Function
          ''' <summary>
          ''' 返回数据集，可以包含多个表，这是我自己加上的，用以返回数据集，表
          ''' </summary>
          ''' <param name="connectionString"></param>
          ''' <param name="cmdType"></param>
          ''' <param name="cmdText"></param>
          ''' <param name="commandParameters"></param>
          ''' <returns></returns>
          ''' <remarks></remarks>
          Public Shared Function ExecuteDataSet(ByVal connectionString As String, ByVal cmdType As CommandType, ByVal cmdText As String, ByVal ParamArray commandParameters As SqlParameter()) As DataSet
              Dim cmd As SqlCommand = New SqlCommand
              Using conn As SqlConnection = New SqlConnection(connectionString)
                  PrepareCommand(cmd, conn, Nothing, cmdType, cmdText, commandParameters)
                  Dim adp As SqlDataAdapter = New SqlDataAdapter(cmd)
                  Dim ds As DataSet = New DataSet
                  Try
                      adp.Fill(ds)
                      cmd.Parameters.Clear()
                  Finally
                      adp.Dispose()
                  End Try
                  Return ds
              End Using
          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 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

          Public Shared Function GetCachedParameters(ByVal cacheKey As String) As SqlParameter()
              Dim cachedParms As SqlParameter() = CType(parmCache(cacheKey), SqlParameter())
              If cachedParms Is Nothing Then Return Nothing
              Dim clonedParms(cachedParms.Length - 1) As SqlParameter
              Dim i As Integer
              For i = 0 To cachedParms.Length - 1
                  clonedParms(i) = CType(CType(cachedParms(i), ICloneable).Clone(), SqlParameter)
              Next
              Return clonedParms
          End Function
          ''' <summary>
          '''
          ''' </summary>
          ''' <param name="cmd"></param>
          ''' <param name="conn"></param>
          ''' <param name="trans"></param>
          ''' <param name="cmdType"></param>
          ''' <param name="cmdText"></param>
          ''' <param name="cmdParms"></param>
          ''' <remarks></remarks>
          Private Shared Sub PrepareCommand(ByVal cmd As SqlCommand, ByVal conn As SqlConnection, ByVal trans As SqlTransaction, ByVal cmdType As CommandType, ByVal cmdText As String, ByVal cmdParms As SqlParameter())
              If conn.State <> ConnectionState.Open Then conn.Open()
              cmd.Connection = conn
              cmd.CommandText = cmdText
              If trans IsNot Nothing Then cmd.Transaction = trans
              cmd.CommandType = cmdType
              If cmdParms IsNot Nothing Then
                  Dim parm As SqlParameter
                  For Each parm In cmdParms
                      cmd.Parameters.Add(parm)
                  Next
              End If
          End Sub
      End Class