MongoDB Common Operations Summary

Operation of ====================================mgdb ======================================

0. The database is created using the (use database name), but if you do not have any other operations (such as a given list) to exit directly after the usage command, then the database executed by the use command will be purged from the buffer pool and not really created! ；

The 1.use command can not only declare the creation of the database but also can switch the database * * *;

2. Delete a database to switch to the database after you use Db.dropdatabase ();

3. Query How many databases are currently logged in to use the show DBS command;

====================================MGDB List Operation ======================================

5. Query the current database has several lists using the show Collections command;

6. Use the db.list name when deleting a list from a database. Drop ();

7. Add a list to the database (the list must have elements) when you first switch to the current database and use the Db.list name. Insert ({name: "ASD", Age: "12"});

Data manipulation in the list of ====================================mgdb ======================================

8. Insert a data in the list using the Db.list name. Insert ({name: "ASD", Age: "12"});

8.1-> If a special list is declared in the database (for example: d-d), you need to use Db.getcollection ("list name") to insert data into such a list. Text.insert ({...}); command, so be aware of the naming;

8.2-> can use insert for bulk data insertion using a for loop;

8.3-> If you name the "_id" key when inserting data to the list and produce duplicate data, using insert will give an error, and using save will change to the same data as the "_id" key;

9. The command to modify a list data is the db.list name. Update ({name: "ASD"},{$set: {name: "BBB"}});

10. Delete a list element db.list name. Remove ({"name": "GG"});

11. Remove all records using the db.list name. Remove (); When the index is not deleted * * * If the amount of data and its large size use the Db.list name. Drop (); High Efficiency * * *

MongoDB Common Operations Summary