时间:2020-09-28来源:www.pcxitongcheng.com作者:电脑系统城
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 } } ) |
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