Question

我在SQL Server Management Studio中运行了一个脚本来测试查询执行的能力。这是批量删除。

DECLARE @Deleted_Rows INT;
SET @Deleted_Rows = 1;

WHILE (@Deleted_Rows > 0)
BEGIN
    BEGIN TRANSACTION

    DELETE TOP (10000) [dbo].[TableA1] 
    WHERE [dbo].[TableA1].[Timestamp] < CAST(CONVERT(VARCHAR(20), GETDATE()-40, 112) + ' 00:00:00' AS DATETIME)

    SET @Deleted_Rows = @@ROWCOUNT;
    COMMIT TRANSACTION
    CHECKPOINT
END

结果非常好，所以我打算将它应用于C＃代码，因为我的主程序在控制台应用程序中运行。该程序处理SELECT，UPDATE，DELETE。

问题是当用于DELETE时，会发生异常：

EXECUTE之后的事务计数表示BEGIN和COMMIT语句的数量不匹配

我使用脚本DELETE的方法：

static async Task StartDeleteRecords(string machname)
{
    try
    {
        int rowsAffected = 0;
        string query = "";

        using (SqlConnection connection = new SqlConnection(localconnstring))
        {
            try
            {
                connection.Open();
                query = @"DECLARE @Deleted_Rows INT;
SET @Deleted_Rows = 1;
WHILE (@Deleted_Rows > 0)
BEGIN
BEGIN TRANSACTION
DELETE TOP (10000)  [dbo].[@tablename]
WHERE [dbo].[@tablename].[Timestamp] < CAST(CONVERT(VARCHAR(20), GETDATE()-@intervaltime, 112) + ' 00:00:00' AS DATETIME)
SET @Deleted_Rows = @@ROWCOUNT;
COMMIT TRANSACTION
CHECKPOINT
END";

                using (SqlCommand command = new SqlCommand(query, connection))
                {
                    command.CommandType = CommandType.Text;
                    command.Parameters.AddWithValue("@tablename", tablename);
                    command.Parameters.AddWithValue("@intervaltime", intervaltime);
                    command.CommandTimeout = 0;

                    rowsAffected = command.ExecuteNonQuery();
                }

                connection.Close();

                LogEvents("Table name: " + tablename + ", Acquire records: " + lstHouseKeep.Count + ", Affected records: " + rowsAffected, EventLogEntryType.Information);
            }
            catch (Exception ex)
            {
                LogEvents("Exception when load data from adapter to generic list. Ex - " + ex.Message, EventLogEntryType.Error);
            }
        }
    }
    catch (Exception ex)
    {
        LogEvents("Exception while start housekeeping records - " + ex.Message, EventLogEntryType.Error);
    }

    await Task.Delay(100);
}

如何在C＃中处理SQL查询循环？

0 个答案: