Upsert and multi in mongodb

The upsert in mongodb and the update in multimongodb are like this: db. XXX. update (query, obj, upsert, multi); For upsert (false by default): If upserttrue is found, if the query finds rows that meet the conditions, modify these rows. If not, append a row that matches query and obj. If the ups

The upsert in mongodb and the update method in multi mongodb are as follows: db. XXX. update (query, obj, upsert, multi); For upsert (false by default): If upsert = true, if the query finds rows that meet the conditions, modify these rows, if not found, append a row that matches query and obj. If the ups

Upsert and multi in mongodb

The update format in mongodb is as follows:

Db. XXX. update (query, obj, upsert, multi );

For upsert (false by default): If upsert = true, if the query finds a row that meets the conditions,

Modify these rows. If no rows are found, append a row that matches query and obj.

If upsert is set to false, no append is added when it cannot be found.

For multi (false by default): If multi is true, all rows that meet the conditions are modified,

Otherwise, only the first row that meets the condition is modified.