mongodb operate update and delete

update name as a to newA,but update one record

db.movies.update({name:'a'},{$set:{name:'newA'}})

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update all

db.movies.update({name:'a'},{$set:{name:'newA'}},{multi:true})

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when save() has _id paramter ,as same as update,otherwise,as insert()

db.movies.save({_id:Object("56461345adsa564"),name:'newA'})

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delete all

db.movies.remove({name:'newB'})

delete one

db.movies.remove({name:'newB'},1)

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remove all records

db.movies.remove()

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restrive specify filed what you want ,1 for yes ,0 for no, default _id is alway exist,can set _id:0

db.movies.find({},{name:1});

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restrive two records,if limit method no paramter,will serach all records

db.movies.find().limit(2)

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skip

db.movies.find().limit(2).skip(1)

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order by filed 1 for Ascending， -1 for descend

db.movies.find().sort({name:-1})

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aggregate

db.movies.aggregate([{$group:{'_id':'$name',num:{$sum:1}}}]) find fileld what you want sum or avge and so more

the result is like:
[{_id:'newA',sum:5},
{_id:'newB',sum:1}]

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thanks ,that is all foundation ,haha.