sql语法和MongoDB语法的对应关系

SQL Statement 

Mongo Query Language Statement 

CREATE TABLE USERS (a Number, b Number)

db.createCollection(

"mycoll", {capped:true

, size:100000})

INSERT INTO USERS VALUES(1,1)

db.users.insert({a:1,b:1})

SELECT a,b FROM users

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

SELECT * FROM users

db.users.find()

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':{$lt: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':{$gt:33,$lte:40}})})

SELECT * FROM users ORDER BY name DESC

db.users.find().sort({name:-1})

CREATE INDEX myindexname ON users(name)

db.users.ensureIndex({name:1})

CREATE INDEX myindexname ON users(name,ts DESC)

db.users.ensureIndex({name:1,ts:-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()

EXPLAIN SELECT * FROM users WHERE z=3

db.users.find({z:3}).explain()

SELECT DISTINCT last_name FROM users

db.users.distinct('last_name')

SELECT COUNT(*y)

FROM users

db.users.count()

SELECT COUNT(*y)

FROM users where AGE > 30

db.users.find({age: {'$gt': 30}}).count()

SELECT COUNT(AGE) from users

db.users.find({age: {'$exists': true}}).count()

UPDATE users SET a=1 WHERE b='q'

db.users.update({b:'q'}, {$set:{a:1}}, false, true)

UPDATE users SET a=a+2 WHERE b='q'

db.users.update({b:'q'}, {$inc:{a:2}}, false, true)

DELETE FROM users WHERE z="abc"

db.users.remove({z:'abc'});