在我的代码中不断弹出错误(连接已打开) [英] an error keeping popping up in my codes (connection already open)

问题描述

这个错误一直弹出！！！MySql.Data.dll 中发生类型为System.InvalidOperationException"的未处理异常

This error keeps popping up!!! An unhandled exception of type 'System.InvalidOperationException' occurred in MySql.Data.dll

附加信息:连接已打开.

Additional information: The connection is already open.

  Dim cmd As MySqlCommand
        con.Open()
        Try
            cmd = con.CreateCommand()
            cmd.CommandText = "update animal_sale set @NOAB,@Amount,@Tax,@Total where Species=@Species"
            cmd.Parameters.AddWithValue("@Species", TextBoxSpecies.Text)
            cmd.Parameters.AddWithValue("@NOAB", TextBoxNo.Text)
            cmd.Parameters.AddWithValue("@Amount", TextBoxAmount.Text)
            cmd.Parameters.AddWithValue("@Tax", TextBoxTax.Text)
            cmd.Parameters.AddWithValue("@Total", TextBoxTotal.Text)
            cmd.ExecuteNonQuery()

            load()
        Catch ex As Exception

        End Try

    End Sub

推荐答案

看起来您在执行查询后没有关闭连接.你只有

It looks like you are not closing the connection after executing the query. You only have

con.Open()

并且在

cmd.ExecuteNonQuery()

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