基于MySQL到MongoDB简易对照表的详解

查询
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})
如果你想在MySQL里添加一个字段，你必须
ALTER TABLE user….
但在MongoDB里你只需要
db.user.insert({‘name' : 'starlee', ‘age' : 25, ‘email' : 'starlee@starlee.'})
删除
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'}, {$inc : {‘age' : 3}})
MySQL:
SELECT COUNT() FROM user WHERE `name` = 'starlee'
Mongo:
db.user.find({‘name' : 'starlee'}).count()
MySQL:
SELECT FROM user limit 10,20
Mongo:
db.user.find().skip(10).limit(20)
MySQL:
SELECT FROM user WHERE `age` IN (25, 35,45)
Mongo:
db.user.find({‘age' : {$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': {$lt : 20}})
MySQL:
SELECT name, sum(marks) FROM user GROUP BY name
Mongo:
db.user.group({
key : {‘name' : true},
cond: {‘name' : ‘foo'},
reduce: function(obj,prev) { prev.msum += obj.marks; },
initial: {msum : 0}
});
MySQL:
SELECT name FROM user WHERE age < 20
Mongo:
db.user.find(‘this.age < 20′, {name : 1})
发现很多人在搜MongoDB循环插入数据，狼蚁网站SEO优化把MongoDB循环插入数据的方法添加在狼蚁网站SEO优化
for(var i=0;i<100;i++)db.test.insert({uid:i,uname:'nosqlfan'+i});
上面一次性插入一百条数据，大概结构如下
{ “_id” : ObjectId(“4c876e519e86023a30dde6b8″), “uid” : 55, “uname” : “nosqlfan55″ }
{ “_id” : ObjectId(“4c876e519e86023a30dde6b9″), “uid” : 56, “uname” : “nosqlfan56″ }
{ “_id” : ObjectId(“4c876e519e86023a30dde6ba”), “uid” : 57, “uname” : “nosqlfan57″ }
{ “_id” : ObjectId(“4c876e519e86023a30dde6bb”), “uid” : 58, “uname” : “nosqlfan58″ }
{ “_id” : ObjectId(“4c876e519e86023a30dde6bc”), “uid” : 59, “uname” : “nosqlfan59″ }
{ “_id” : ObjectId(“4c876e519e86023a30dde6bd”), “uid” : 60, “uname” : “nosqlfan60″ }
简易对照表
SQL Statement                                                  Mongo Query Language Statement
CREATE TABLE USERS (a Number, b Number)         implicit; can be done explicitly
INSERT INTO USERS VALUES(1,1)                             db.users.insert({a:1,b:1})
SELECT a,b FROM users                                           db.users.find({}, {a:1,b:1})
SELECT FROM users                                              db.users.find()
SELECT FROM users WHERE age=33                      db.users.find({age:33})
SELECT a,b FROM users WHERE age=33                   db.users.find({age:33}, {a:1,b:1})
SELECT FROM users WHERE age=33 ORDER BY name                db.users.find({age:33}).sort({name:1})
SELECT FROM users WHERE age>33                     db.users.find({'age':{$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