First, create a database
Second, to see all databases
Third, delete the database
Fourth, create a collection
Fifth, delete collections
Sixth, a collection of usage presentation
1, create a collection
2, delete the collection
First, create a database
Second, to see all databases
Third, delete the database
Fourth, create a collection
Fifth, delete collections
Sixth, a collection of usage presentation
1, create a collection
2, delete the collection