Life Thunder Dog MongoDB----MONGODB---2---common commands and tricks

To see which databases are available:

Show DBS

Switch to that library:

Use library name

 Use Local

Use also has a function of "Create a Database"

 Use test

To delete a database:

Db.dropdatabase ();

To view a collection:

Show collections

To create a collection:

Db.createcollection ("user");

Implicitly created, inserted directly into the collection, she will automatically create the collection

Db. user. Insert ({ID:1, Name: "Lisi"});

To delete a collection:

Db. user. Drop ();

Insert:

Db. user. Insert ({ID:1, Name: "Lisi", Sex: "1"});

Inquire:

Db. user. Find ()

Modify:

Db. user. Update ({ID:1},{name:'Lisi', Sex:'1'});

Delete:

Db. user. Remove ({name:'Lisi'});

If you insert two identical parameters at the same time, they will be overwritten by the following

Db. user. Insert ({x:2, x:3});

It's strictly case-sensitive in MongoDB.

If you want to make time a non-string form in real-world development, you can insert data by using the new date method:

Db. user. Insert ({name:'Lisi', Addtime:new Date ()});

If the direct date () is created as a string, the

If you do not want to see him print out the default generated heap of _id strings at the time of printing, we can query by the following methods:

Db. user. Find ({},{_id:0});

If _id:1 then print out the default _id

Life Thunder Dog MongoDB----MONGODB---2---common commands and tricks