查詢：
MySQL:
SELECT * FROM user
Mongo:
db.user.find()
?
MySQL:
SELECT * FROM user WHERE name = 'starlee'
Mongo:
db.user.find({'name' : 'starlee'})
插入：
MySQL:
INSERT INOT user (`name`, `age`) values ('starlee',25)
Mongo:
db.user.insert({'name' : 'starlee', 'age' : 25})
?
if you want add a column `email` on MySQL,you must :
ALTER TABLE user….
But in Mongo,you can just:
db.user.insert({'name' : 'starlee', 'age' : 25, 'email' : '[email protected]'})
?
刪除：
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 : <= ; $ne : !=
?
更新:
?
?MySQL:
UPDATE user SET `age` = 36 WHERE `name` = 'starlee'
Mongo:
db.user.update({'name' : 'starlee'}, {$set : {'age' : 36}})
?
MySQL:
UPDATE user SET `age` = `age` + 3 WHERE `name` = 'starlee'
Mongo:
db.user.update({'name' : 'starlee'}, {$inc : {'age' : 3}})
?
==============Split=======================
MySQL:
SELECT COUNT(*) FROM user WHERE `name` = 'starlee'
Mongo:
db.user.find({'name' : 'starlee'}).count()
?
MySQL:
SELECT * FROM user limit 10,20
Mongo:
db.user.find().skip(10).limit(20)
?
MySQL:
SELECT * FROM user WHERE `age` IN (25, 35,45)
Mongo:
db.user.find({'age' : {$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})