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。
{
_id: new ObjectId("63bad43ee5d01d4cc13d58b2"),
title: '测试任务',
completed: false,
urgent: false,
assignedBy: new ObjectId("63afc89d7e3da6e5d996d415"), // 例如：约翰
asignTo: new ObjectId("63bac632f2f1830832d229a4"), // 例如：戴维
__v: 0
}
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。
{
_id: new ObjectId("63bad43ee5d01d4cc13d58b2"),
title: '测试任务',
completed: false,
urgent: false,
assignedBy: new ObjectId("63afc89d7e3da6e5d996d415"), // 例如：约翰
asignTo: new ObjectId("63afc89d7e3da6e5d996d415"), // 例如：约翰
__v: 0
}
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.
{
_id: new ObjectId("63bad43ee5d01d4cc13d58b2"),
title: 'Test task',
completed: false,
urgent: false,
assignedBy: new ObjectId("63afc89d7e3da6e5d996d415"), // ex: john
asignTo: new ObjectId("63bac632f2f1830832d229a4"), // ex: devid
__v: 0
}
when I delete devid user from the db I want to assign his task to the john and save the task
{
_id: new ObjectId("63bad43ee5d01d4cc13d58b2"),
title: 'Test task',
completed: false,
urgent: false,
assignedBy: new ObjectId("63afc89d7e3da6e5d996d415"), // ex: john
asignTo: new ObjectId("63afc89d7e3da6e5d996d415"), // ex: john
__v: 0
}
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）：
const updateAndDelete = async (userToRemove) => {
const session = await db.startSession()
try {
session.startTransaction();
const user = await User.findById(userToRemove, {session: session})
const {assignedBy} = user
await user.remove({session: session})
await Task.updateMany({asignTo: userToRemove}, {asignTo: assignedBy}, {session: session})
await session.commitTransaction();
} catch(e) {
await session.abortTransaction();
}
session.endSession();
}
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):
const updateAndDelete = async (userToRemove) => {
const session = await db.startSession()
try {
session.startTransaction();
const user = await User.findById(userToRemove, {session: session})
const {assignedBy} = user
await user.remove({session: session})
await Task.updateMany({asignTo: userToRemove}, {asignTo: assignedBy}, {session: session})
await session.commitTransaction();
} catch(e) {
await session.abortTransaction();
}
session.endSession();
}
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.
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论