如何在mongodb中进行批量更新和删除操作？

huangapple
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英文:

How update and delete bulk operation in mongodb?

问题

我正在构建一个任务管理应用程序，只有管理员可以删除用户。当管理员删除一个用户时，我希望将被删除用户的任务分配给由他指定的用户。

  1. {
  2.   _id: new ObjectId("63bad43ee5d01d4cc13d58b2"),
  3.   title: '测试任务',
  4.   completed: false,
  5.   urgent: false,
  6.   assignedBy: new ObjectId("63afc89d7e3da6e5d996d415"), // 例如：约翰
  7.   asignTo: new ObjectId("63bac632f2f1830832d229a4"), // 例如：戴维
  8.   __v: 0
  9. }

当我从数据库中删除戴维用户时，我希望将他的任务分配给约翰并保存任务。

  1. {
  2.   _id: new ObjectId("63bad43ee5d01d4cc13d58b2"),
  3.   title: '测试任务',
  4.   completed: false,
  5.   urgent: false,
  6.   assignedBy: new ObjectId("63afc89d7e3da6e5d996d415"), // 例如：约翰
  7.   asignTo: new ObjectId("63afc89d7e3da6e5d996d415"), // 例如：约翰
  8.   __v: 0
  9. }
英文:

I'm building a taskmanagment application, where only admin can delete user. when admin delete a user, I want to assign deleted users task to the his assignby user.

  1. {
  2.   _id: new ObjectId("63bad43ee5d01d4cc13d58b2"),
  3.   title: 'Test task',
  4.   completed: false,
  5.   urgent: false,
  6.   assignedBy: new ObjectId("63afc89d7e3da6e5d996d415"), // ex: john
  7.   asignTo: new ObjectId("63bac632f2f1830832d229a4"), // ex: devid
  8.   __v: 0
  9. }

when I delete devid user from the db I want to assign his task to the john and save the task

  1. {
  2.   _id: new ObjectId("63bad43ee5d01d4cc13d58b2"),
  3.   title: 'Test task',
  4.   completed: false,
  5.   urgent: false,
  6.   assignedBy: new ObjectId("63afc89d7e3da6e5d996d415"), // ex: john
  7.   asignTo: new ObjectId("63afc89d7e3da6e5d996d415"), // ex: john
  8.   __v: 0
  9. }

答案1

得分: 0

我认为你正在寻找transactions以避免数据丢失。

因此，你可以尝试类似以下的代码（这不是真实的代码）：

  1. const updateAndDelete = async (userToRemove) => {
  2.     const session = await db.startSession()
  3.     try {
  4.         session.startTransaction();
  5.         const user = await User.findById(userToRemove, {session: session})
  6.         const {assignedBy} = user
  7.         await user.remove({session: session})
  8.         await Task.updateMany({asignTo: userToRemove}, {asignTo: assignedBy}, {session: session})
  9.         await session.commitTransaction();
  10.     } catch(e) {
  11.         await session.abortTransaction();
  12.     }
  13.     session.endSession();
  14. }

如果一切正常，你可以提交事务并保存所有更改（你还可以添加一些 if 来抛出异常，如果需要的话），否则你可以回滚，不会有任何数据丢失。

英文:

I think you are looking for transactions to avoid loss data.

So you can try somethig like (not real code):

  1. const updateAndDelete = async (userToRemove) => {
  2.     const session = await db.startSession()
  3.     try {
  4.         session.startTransaction();
  5.         const user = await User.findById(userToRemove, {session: session})
  6.         const {assignedBy} = user
  7.         await user.remove({session: session})
  8.         await Task.updateMany({asignTo: userToRemove}, {asignTo: assignedBy}, {session: session})
  9.         await session.commitTransaction();
  10.     } catch(e) {
  11.         await session.abortTransaction();
  12.     }
  13.     session.endSession();
  14. }

If everything is ok, you commit the transaction and all changes are saved (also you can add some if an thorw an exception if you want), otherwise you can do a rollback and there is not any data loss.

huangapple
  • 本文由 发表于 2023年1月8日 23:14:24
  • 转载请务必保留本文链接：https://go.coder-hub.com/75048897.html
  • javascript
  • mern
  • mongodb
  • mongoose
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