MongoDB Database Common Operations

First, the database operation

1. View the current database name

2. View all database names

3. Toggles the database if the database does not exist and is not created until the database is created when the data is inserted or the collection is created

4. Delete the currently pointing database and do nothing if the database does not exist

Second, set operation

1. Create a Collection

2. View a collection of current databases

3. Delete Collection

Third, data additions and deletions to change

1. Inserting data

Note: If you do not specify _ID,MONGODB when inserting data, you will automatically assign a

2. Update data

3. Save Data

4. Delete

iv. data Query

1. Search All

2. Querying a single piece of data

3. Format Query

　 comparison Operators

4. query for age greater than or equal to 18

　 logical operators $or and and

5. Scope Query

6. Gets the specified data entry limit

7. Skip the specified entry skip

8. Projection (just show the fields you want to see)

9. Sort

10. Statistics Count

11. Go to heavy distinct

Five, aggregate function Aggregate

Common expressions

For example:total number of students, average age

Pivot data (that is, the data is displayed in categories)

For example: statistics on student gender and student name

Vi. Index

1. Create an index

2. The ability to create unique indexes to implement unique constraints

3. View all indexes on a document

4. Delete Index

Vii. Backup

1. Backing up data

2. Recovering Data

MongoDB Database Common Operations