Question

我在SQL Server中迭代incidentNoReserve tbl。单击按钮时，如果它与变量匹配，则整行将从incidentNoReserve tbl中删除。

这是代码：

private void button3_Click(object sender, EventArgs e)
{
    try
    {
        using (var cmd106 = new SqlCommand("select * from [dbo].[incidentNoReserve]", cnn))
        {
            cnn.Open();

            SqlDataReader reader = cmd106.ExecuteReader();

            while (reader.Read())
            {
                var commonNo = reader["incidentNoReserveId"];
                //Every new row will create a new dictionary that holds the columns
                if (Convert.ToInt16(commonNo) == newLastIncidentNo )
                {
                    var cmd107 = new SqlCommand("Delete from[dbo].[incidentNoReserve] where incidentNoReserveId = @newLastIncidentNo", cnn);
                    cmd107.Parameters.AddWithValue("@newLastIncidentNo", newLastIncidentNo);
                    cmd107.ExecuteNonQuery();
                }

                cnn.Close();
            }

            reader.Close();
        }
    }
    catch (Exception ex)
    {
        // If an exception occurs, write it to the console
        Console.WriteLine(ex.ToString());
    }
    finally
    {
        cnn.Close();
    }

    this.Close();
}

newLastIncidentNo有18个，当它到达commonNo时它有10个，它只是incidentNoReserve表中的第一行。

可能是什么问题？

Answer 1

您正在关闭循环

中的连接

您正在使用相同的连接来循环和更新

Answer 2

它工作我刚刚删除了内部打开和关闭连接。谢谢所有

Answer 3

我这样修理：

 while (reader.Read())
                    {
                        int commonNo = Convert.ToInt16(reader["incidentNoReserveId"]);
                        //Every new row will create a new dictionary that holds the columns
                        if (Convert.ToInt16(commonNo) == newLastIncidentNo)
                        {
                            reader.Close();
                            //newLastIncidentNo = (Convert.ToInt16(commonNo));
                            using (SqlCommand command = new SqlCommand("Delete from [dbo].[incidentNoReserve] where incidentNoReserveId = @newLastIncidentNo", cnn))
                            {

                                //MessageBox.Show(newLastIncidentNo.ToString());
                                command.Parameters.AddWithValue("@newLastIncidentNo", newLastIncidentNo);
                                command.ExecuteNonQuery();

                            }
                        }
                    }

                    cnn.Close();
                }
            }
            catch (Exception ex)

使用datareader在SQL Server中迭代表

3 个答案: