MongoDB学习六--MongoDB删除数据文档

In MongoDB, the db.collection.remove() method
removes documents from a collection. You can remove all documents from a collection, remove all documents that match a condition, or limit the operation to remove just a single document.

To
remove all documents from a collection, pass an empty query document {} to
the remove() method.
The remove() method
does not remove the indexes.

db.admin.remove({})

To remove all documents from a collection, it may be more efficient to use the drop() method
to drop the entire collection, including the indexes, and then recreate the collection and rebuild the indexes.

To
remove the documents that match a deletion criteria, call the remove() method
with the <query>parameter.

db.admin.remove( { type : "food" } )

For large deletion operations, it may be more efficient to copy the documents that you want to keep to a new collection and
then use drop() on
the original collection.

To
remove a single document, call the remove() method
with the justOne parameter
set to true or 1.

db.admin.remove( { type : "food" }, 1 )

To delete a single document sorted by some specified order, use the findAndModify() method.