NoSql journey-mongoDB shell command summary, nosql-mongodb

NoSql journey-mongoDB shell command summary, nosql-mongodb
MongoDB three elements. Database, set, and document.


A set is equivalent to a table in a relational database, and a document is equivalent to a row in a table.




Document is json extension (Bson form)


MongoDB basic addition, deletion, modification, and query
Insert
Db. tablename. insert ({Bson format });


Find
Db. tablename. find () query all


Db. tablename. find ({Bson format}) query by keyword


Update
Db. tablename. update ({},{}) the first parameter is the query condition, and the second parameter is the updated value.


Remove
Db. person. remove () delete all records, which cannot be undone.
Db. person. remove ({}) is deleted based on conditions.
Db. person. count () Total number of records.