MongoDB与SQL常用语法对应表

    对于经常写SQL的同学，一开始写mongoDB的语法会十分不习惯，下表整理了常见的SQL语法，函数以及相应的MongoDB对应语法，仅供参考。

 

术语及概念

SQL	MongoDB
database	database
table	collection
row	document
column	field
index	index
table joins	$lookup
primary key	primary key
SELECT INTO NEW_TABLE	$out
MERGE INTO TABLE	$merge(mongodb > 4.2)
UNION ALL	$unionWith (mongodb > 4.4)
transactions	transactions

 

语法对应表

SQL	MongoDB
CREATE TABLE people (     id MEDIUMINT NOT NULL         AUTO_INCREMENT,     user_id Varchar(30),     age Number,     status char(1),     PRIMARY KEY (id) )	db.createCollection("people")   db.people.insertOne( {     user_id: "abc123",     age: 55,     status: "A"  } )
ALTER TABLE people ADD join_date DATETIME	db.people.updateMany(     { },     { $set: { join_date: new Date() } } )
ALTER TABLE people DROP COLUMN join_date	db.people.updateMany(     { },     { $unset: { "join_date": "" } } )
CREATE INDEX idx_user_id_asc ON people(user_id)	db.people.createIndex( { user_id: 1 } )
CREATE INDEX        idx_user_id_asc_age_desc ON people(user_id, age DESC)	db.people.createIndex( { user_id: 1, age: -1 } )
DROP TABLE people	db.people.drop()
INSERT INTO people(user_id,                   age,status) VALUES ("bcd001",45,"A")	db.people.insertOne(    { user_id: "bcd001", age: 45, status: "A" } )
SELECT * FROM people	db.people.find()
SELECT id,        user_id,        status FROM people	db.people.find(     { },     { user_id: 1, status: 1 } )
SELECT user_id, status FROM people	db.people.find(     { },     { user_id: 1, status: 1, _id: 0 } )
SELECT user_id, status FROM people WHERE status = "A"	db.people.find(     { status: "A" },     { user_id: 1, status: 1, _id: 0 } )
SELECT * FROM people WHERE status != "A"	db.people.find(     { status: { $ne: "A" } } )
SELECT * FROM people WHERE status = "A" AND age = 50	db.people.find(     { status: "A",       age: 50 } )
SELECT * FROM people WHERE status = "A" OR age = 5	db.people.find(     { $or: [ { status: "A" } , { age: 50 } ] } )
SELECT * FROM people WHERE age > 25 AND   age <= 50	db.people.find(    { age: { $gt: 25, $lte: 50 } } )
SELECT * FROM people WHERE user_id like "%bc%	db.people.find( { user_id: /bc/ } ) -or- db.people.find( { user_id: { $regex: /bc/ } } )
SELECT * FROM people WHERE user_id like "bc%"	db.people.find( { user_id: /^bc/ } ) -or- db.people.find( { user_id: { $regex: /^bc/ } } )
SELECT * FROM people WHERE status = "A" ORDER BY user_id AS	db.people.find( { status: "A" } ).sort( { user_id: 1 } )
SELECT COUNT(*) FROM people	db.people.count() or db.people.find().count()
SELECT COUNT(user_id) FROM people	db.people.count( { user_id: { $exists: true } } ) or db.people.find( { user_id: { $exists: true } } ).count()
SELECT COUNT(*) FROM people WHERE age > 30	db.people.count( { age: { $gt: 30 } } ) or db.people.find( { age: { $gt: 30 } } ).count()
SELECT DISTINCT(status) FROM people	db.people.aggregate( [ { $group : { _id : "$status" } } ] ) or db.people.distinct( "status" )
EXPLAIN SELECT * FROM people WHERE status = "A"	db.people.find( { status: "A" } ).explain()
UPDATE people SET age = age + 3 WHERE status = "A"	db.people.updateMany(    { status: "A" } ,    { $inc: { age: 3 } } )