What is the difference between save and insert in Mongo DB?
Let us consider the two cases here for save :-
1) Having _id in doc.
2) Not having _id in doc.
Save ()
/ \
/ \
Having _id Not Having _id
->In this case save will do -> It will do normal insertion
upsert to insert.Now in this case as insert() do.
what that means, it means
take the document and replace
the complete document having same
_id.
Let us consider the two cases here for insert:-
1) Having _id of doc in collection.
2) Not having _id of doc in collection.
Insert()
/ \
/ \
Doc Having _id in collection Doc Not Having _id
-> E11000 duplicate key ->Insert a new doc inside the collection.
error index:
Save Vs Insert :
In your given examples, the behavior is essentially the same.
save
behaves differently if it is passed with an "_id" parameter.
For save, If the document contains _id
, it will upsert querying the collection on the _id
field, If not, it will insert.
If a document does not exist with the specified _id value, the save() method performs an insert with the specified fields in the document.
If a document exists with the specified _id value, the save() method performs an update, replacing all field in the existing record with the fields from the document.
Save vs Update :
update
modifies an existing document matched with your query params. If there is no such matching document, that's when upsert
comes in picture.
upsert : false
: Nothing happens when no such document existupsert : true
: New doc gets created with contents equal to query params and update params
save
: Doesn't allow any query-params. if _id
exists and there is a matching doc with the same _id
, it replaces it. When no _id specified/no matching document, it inserts the document as a new one.