Question

有人知道为什么在cmd.ExecuteNonQuery()上运行的代码为什么会出现异常？当我更新日期时，它运行得很好，但是当我更新完成日期时，出现了该错误。这是代码

Call connection()
    If txt_UpCom.Text = "" Or cbCom.SelectedItem = "" Then
        If txt_ComNew.Enabled = True Then
            MessageBox.Show("Please fill the entire data!")
        End If
    Else
        Try
            Dim str As String
            If cbCom.SelectedItem = "Date" Or cbCom.SelectedItem = "Finish Date" Then
                Dim comdate As String = dateCom.Value.ToString("yyyy-MM-dd")
                str = "UPDATE complain SET " & cbCom.SelectedItem & "= '" & comdate & "' WHERE ComplainID = '" & txt_UpCom.Text & "'"
            Else
                str = "UPDATE complain SET " & cbCom.SelectedItem & " = '" & txt_ComNew.Text & "' WHERE ComplainID = '" & txt_UpCom.Text & "'"
            End If
            cmd = New MySql.Data.MySqlClient.MySqlCommand(str, conn)
            cmd.ExecuteNonQuery()
            msgBoxSuccess.ShowDialog()
            conn.Close()
        Catch ex As Exception
            MessageBox.Show("Unable to Update")
        End Try
    End If

This is the table in database

Answer 1

正如@JacekWróbel在评论中提到的那样，您应将列名保持在[]（方括号）或“”（双引号）之间。表名（或与此相关的任何其他SQL对象）也一样。

长话短说，更改代码的这一部分：

            If cbCom.SelectedItem = "Date" Or cbCom.SelectedItem = "Finish Date" Then
                Dim comdate As String = dateCom.Value.ToString("yyyy-MM-dd")
                str = "UPDATE complain SET " & cbCom.SelectedItem & "= '" & comdate & "' WHERE ComplainID = '" & txt_UpCom.Text & "'"
            Else
                str = "UPDATE complain SET " & cbCom.SelectedItem & " = '" & txt_ComNew.Text & "' WHERE ComplainID = '" & txt_UpCom.Text & "'"
            End If

对此：

            If cbCom.SelectedItem = "Date" Or cbCom.SelectedItem = "Finish Date" Then
                Dim comdate As String = dateCom.Value.ToString("yyyy-MM-dd")
                str = "UPDATE `complain` SET `" & cbCom.SelectedItem & "` = '" & comdate & "' WHERE `ComplainID` = '" & txt_UpCom.Text & "'"
            Else
                str = "UPDATE `complain` SET `" & cbCom.SelectedItem & "` = '" & txt_ComNew.Text & "' WHERE `ComplainID` = '" & txt_UpCom.Text & "'"
            End If

注意：我希望保持事物的一致性，因此我向每个对象添加了[]，无论它是否包含空格。

需要帮助来更新vb.net中的数据库

1 个答案: