Question

我是vb的新手，我正在创建一个项目，我可以编辑帐户到目前为止我遇到了问题。当我的数据库中的值为NULL

时，.read函数停止

ElseIf ButtonChoice = 2 Then
            txtIDnumber.Text = val
            Dim EditFamilyProfile As New SqlCommand("Select * From [186].[dbo].[familyInfo] WHERE pFnumber = @pFnumber", Connection)
            EditFamilyProfile.CommandType = CommandType.Text
            EditFamilyProfile.Parameters.AddWithValue("@pFnumber", txtIDnumber.Text)
            Dim drEdit As SqlDataReader
            drEdit = EditFamilyProfile.ExecuteReader
            With drEdit
                .Read()
                txtLastName.Text = .Item(1)
                txtFirstName.Text = .Item(2)
                txtMiddleName.Text = .Item(3)
                txtExt.Text = .Item(4)
                txtAddress.Text = .Item(5)
                cmbGender.Text = .Item(6)
.close()
            End With
        End If

它在txteExt.text中停止，因为它具有NULL值。没有显示错误。它只是去代码：

  ButtonChoice = 2
        Dim obb As New frm_FamilyReg
        obb.val = Me.txtIDnumber.Text()
        obb.Show()
        Me.Close()

Answer 1

使用IsDBNull()函数检查您是否有dbNUll值，如果有，请跳过它。

if not IsDBNull(txtLastName.Text = .Item(1)) then
   txtLastName.Text = .Item(1)
End If

当数据库中的值为NULL时，SqlDataReader停止

1 个答案: