Question

mongodb中查询和sql查询之间的关系

Answer 1

Sql

Mongodb

SELECT * FROM users

Db.users.find()

SELECT a,b FROM users

Db.users.find({},{a:1,b:1})

SELECT * FROM users WHERE age=33

Db.users.find({age:33})

SELECT a,b FROM users WHERE age=33

Db.users.find({age:33},{a:1,b:1})

SELECT * FROM users WHERE age=33 ORDER BY name

Db.users.find({age:33}).sort({name:1})

SELECT * FROM users WHERE age>33

Db.users.find({age:{“$gt”:33}})

SELECT * FROM users WHERE age!=33

Db.users.find({age:{“$ne”:33}})

SELECT * FROM users WHERE name LIKE "%Joe%"

Db.users.find({name:”\Joe\”})

SELECT * FROM users WHERE name LIKE "Joe%"

Db.users.find({name:\^Joe\})

SELECT * FROM users WHERE age>33 AND age<=40

Db.users.find({age:{“$gt”:33},age:{“lte”:40}})

SELECT * FROM users ORDER BY name DESC

Db.user.find().sort({name:-1})

SELECT * FROM users WHERE a=1 and b='q'

Db.users.find({a:1,b:”q”})

SELECT * FROM users LIMIT 10 SKIP 20

Db.users.find().limit(10).skip(20)

SELECT * FROM users WHERE a=1 or b=2

db.users.find( { $or : [ { a : 1 } , { b : 2 } ] } )

SELECT * FROM users LIMIT 1

Db.users.findOne()

SELECT order_id FROM orders o, order_line_items li WHERE li.order_id=o.order_id AND li.sku=12345

db.orders.find({"items.sku":12345},{_id:1})