From MySQL to MongoDB (add MongoDB to insert data cyclically)

Reprinted from nosqlfan. view the original article

This article describes how to write common SQL statements in MySQL in MongoDB. If you are eager to try using MySQL for a long time, this simple article will help you enter the role more quickly.

Query:
MySQL:
Select * from user
Mongo:
DB. User. Find ()

MySQL:
Select * from user where name = 'starlil'
Mongo:
DB. User. Find ({'name': 'starlil '})

Insert:
MySQL:
Insert inot user ('name', 'age') values ('starlil', 25)
Mongo:
DB. User. insert ({'name': 'starlee ', 'age': 25 })

To add a field to MySQL, you must:
Alter table user ....
However, in MongoDB, you only need:
DB. User. insert ({'name': 'starlee ', 'age': 25, 'email': 'starlee @ starlee.com '})

Delete:
MySQL:
Delete * from user
Mongo:
DB. User. Remove ({})

MySQL:
Delete from user where age <30
Mongo:
DB. User. Remove ({'age': {$ LT: 30 }})

$ GT: >;$ GTE: >=;$ lt :<;$ LTE :<=; $ ne :! =

Update:

MySQL:
Update user set 'age' = 36 where 'name' = 'starlil'
Mongo:
DB. User. Update ({'name': 'starlil'}, {$ set: {'age': 36 }})

MySQL:
Update user set 'age' = 'age' + 3 where 'name' = 'starlil'
Mongo:
DB. User. Update ({'name': 'starlil'}, {$ Inc: {'age': 3 }})

MySQL:
Select count (*) from user where 'name' = 'starlil'
Mongo:
DB. User. Find ({'name': 'starlil'}). Count ()

MySQL:
Select * from user limit 10, 20
Mongo:
DB. User. Find (). Skip (10). Limit (20)

MySQL:
Select * from user where 'age' in (25, 35, 45)
Mongo:
DB. User. Find ({'age': {$ in: [25, 35, 45]})

MySQL:
Select * from user order by age DESC
Mongo:
DB. User. Find (). Sort ({'age':-1 })

MySQL:
Select distinct (name) from user where age> 20
Mongo:
DB. User. Distinct ('name', {'age': {$ LT: 20 }})

MySQL:
Select name, sum (marks) from user group by name
Mongo:
DB. User. Group ({
Key: {'name': true },
Cond: {'name': 'foo '},
Reduce: function (OBJ, Prev) {Prev. msum + = obj. Marks ;},
Initial: {msum: 0}
});

MySQL:
Select name from user where age <20
Mongo:
DB. User. Find ('this. age <20', {Name: 1 })

Many people found that they are searching for MongoDB to insert data cyclically. The following describes how to insert data cyclically in MongoDB:

For (VAR I = 0; I <100; I ++) dB. Test. insert ({uid: I, uname: 'nosqlfan '+ I });

Insert one hundred data records at a time. The approximate structure is as follows:

{"_ ID": objectid ("4c876e519e86023a30dde6b8"), "uid": 55, "uname": "nosqlfan55"} {"_ ID": objectid ("Comment ″), "uid": 56, "uname": "nosqlfan56"} {"_ ID": objectid ("4c876e519e86023a30dde6ba"), "uid": 57, "uname ": "nosqlfan57"} {"_ ID": objectid ("4c876e519e86023a30dde6bb"), "uid": 58, "uname": "nosqlfan58"} {"_ ID ": objectid ("identifier"), "uid": 59, "uname": "nosqlfan59"} {"_ ID": objectid ("4c876e519e86023a30dde6bd"), "uid": 60, "uname": "nosqlfan60 ″}