Sql server ExecuteSQLCommand将布尔值从False更改为NULL

我有一个WebInvoke方法：

  <OperationContract()>
  <WebInvoke(Method:="POST", ResponseFormat:=WebMessageFormat.Json)>
  Public Function Actions_Update_ByID(ByVal aID As Int32, Optional aActionID As Int32 = Nothing, Optional aConsequence_Paid As Boolean = Nothing, Optional aDate As DateTime = Nothing, Optional aName As String = Nothing, Optional aNotes As String = Nothing, Optional aReward_Paid As Boolean = Nothing) As String
    Try
      Dim c As New Common
      Dim ps As SqlParameter() = {New SqlParameter("@ID", SqlDbType.Int), New SqlParameter("@ActionID", SqlDbType.Int), New SqlParameter("@Consequence_Paid", SqlDbType.Bit), New SqlParameter("@Date", SqlDbType.DateTime), New SqlParameter("@Name", SqlDbType.NVarChar), New SqlParameter("@Notes", SqlDbType.NVarChar), New SqlParameter("@Reward_Paid", SqlDbType.Bit)}
      ps(0).Value = aID
      ps(1).Value = IIf(aActionID = Nothing, DBNull.Value, aActionID)
      ps(2).Value = IIf(aConsequence_Paid = Nothing, DBNull.Value, aConsequence_Paid)
      ps(3).Value = IIf(aDate = Nothing, DBNull.Value, aDate)
      ps(4).Value = IIf(aName = Nothing, DBNull.Value, aName)
      ps(5).Value = IIf(aNotes = Nothing, DBNull.Value, aNotes)
      ps(6).Value = IIf(aReward_Paid = Nothing, DBNull.Value, aReward_Paid)
      c.ExecuteSQLCommand("UPDATE [Actions] SET [ActionID] = @ActionID,[Consequence_Paid] = @Consequence_Paid,[Date] = @Date,[Name] = @Name,[Notes] = @Notes,[Reward_Paid] = @Reward_Paid WHERE [ID] = @ID", ps)
      Return (New JavaScriptSerializer()).Serialize(String.Empty)
    Catch ex As Exception
      Dim row As New Dictionary(Of String, String) From {{"error", ex.Message}}
      Return (New JavaScriptSerializer()).Serialize(row)
    End Try
  End Function

此处的ExecuteSQLCommand：

  Sub ExecuteSQLCommand(ByVal commandText As String, ByVal params As SqlParameter())
    Dim con As New SqlConnection(GetConnectionString())
    Try
      con.Open()

      Dim com As New SqlCommand(commandText, con)
      If Not params Is Nothing Then
        If params.Count > 0 Then
          com.Parameters.AddRange(params)
        End If
      End If
      com.ExecuteNonQuery()

    Finally
      If con.State = ConnectionState.Open Then
        con.Close()
      End If
    End Try
  End Sub

所以，每次我向布尔参数发送False（aConsequence\u Paid，aReward\u Paid）时，我在数据库中得到Null值，如何

谢谢， 德扬

可选基本参数的默认值永远不能是

Nothing

。通过指定

Nothing

，未提供的任何参数将默认为各自的默认值，因此

aConsequence\u Paid

将为false

Iif

比较将是错误的比较，因此

false=Nothing

将计算为true

因此，如果没有提供值，或者提供了false，那么DbNull将被传递给查询

我建议使用可空类型

Public Function Actions_Update_ByID(Optional aConsequence_Paid = As Boolean? = Nothing)
  ' ...
  ps(2).Value = IIf(aConsequence_Paid.HasValue, aConsequence_Paid.Value, DBNull.Value)
  ' ...
End Function

可选基本参数的默认值永远不能是

Nothing

。通过指定

Nothing

，未提供的任何参数将默认为各自的默认值，因此

aConsequence\u Paid

将为false

Iif

比较将是错误的比较，因此

false=Nothing

将计算为true

因此，如果没有提供值，或者提供了false，那么DbNull将被传递给查询

我建议使用可空类型

Public Function Actions_Update_ByID(Optional aConsequence_Paid = As Boolean? = Nothing)
  ' ...
  ps(2).Value = IIf(aConsequence_Paid.HasValue, aConsequence_Paid.Value, DBNull.Value)
  ' ...
End Function