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MySQL Workbench：启动事务似乎在回滚之前提交(MySQL Workbench: Start Transaction seems to be committed before rollback)

 我写了一堆删除语句并将它们包装在一个事务中：  
start transaction;
delete a...
delete b...
delete c...
rollback;
 
 我的想法是，我希望删除发生在事务中，该事务将在完成时回滚。 如果步骤失败，我希望成功的步骤也可以回滚。  
 令我懊恼的是delete a工作，删除几千行， delete b失败，但当我重新声明时，所有来自a的记录似乎都消失了。  
 这是因为交易还在开放吗？ 我尝试过：  
set session transaction isolation level read committed;
select a.*
 
 并回到零行，所以我认为情况并非如此。 删除是否成功？ 如果是这样，我怎样才能防止这种情况发生，直到我能保证完整的查询？ 

I wrote a bunch of delete statements and wrapped them in a transaction: 
start transaction;
delete a...
delete b...
delete c...
rollback;
 
The idea is I would want the deletes to occur inside a transaction which would rollback upon completion. If a step failed along the way, I would want the successful steps to be rolled back as well. 
To my chagrin delete a worked, removing a few thousand rows, delete b failed, but when I reran the statements all the records from a appeared to be gone. 
Is this because the transaction is still open? I tried doing: 
set session transaction isolation level read committed;
select a.*
 
and got back zero rows so I think that is not the case. Was the successful a delete committed? And if so, how do I prevent that from happening until I can guarantee a full working query?

原文：https://stackoverflow.com/questions/37400283

更新时间：2022-05-15 14:05

最满意答案

 这是一个想法的骨架：  
#!/bin/bash
exec 5< <(sleep 4; pwd)
while true
do
  if
    read -t 0 -u 5 dummy
  then
    echo Data available
    cat <&5
    break
  else
    echo No data
  fi
  sleep 1
done
 
 从Bash参考手册：  
 
  如果timeout为0，则read立即返回，而不尝试读取和数据。 如果输入在指定的文件描述符上可用，则退出状态为0，否则为非零。  
 
 想法是使用带有-t 0读取（具有零超时）和-u 5 （从文件描述符5读取）以立即检查数据可用性。  
 当然，这只是展示概念的玩具循环。 

Here is the skeleton of an idea : 
#!/bin/bash
exec 5< <(sleep 4; pwd)
while true
do
  if
    read -t 0 -u 5 dummy
  then
    echo Data available
    cat <&5
    break
  else
    echo No data
  fi
  sleep 1
done
 
From the Bash reference manual : 
 
 If timeout is 0, read returns immediately, without trying to read and data. The exit status is 0 if input is available on the specified file descriptor, non-zero otherwise. 
 
The idea is to use read with -t 0 (to have zero timeout) and -u 5 (read from file descriptor 5) to instantly check for data availability. 
Of course this is just a toy loop to demonstrate the concept.

MySQL Workbench：启动事务似乎在回滚之前提交(MySQL Workbench: Start Transaction seems to be committed before rollback)

最满意答案

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