??????????????????

???????SQL SERVER??????????
????sql server 2005??????汾?????? rownum() over()??????
??????????rownum() over()????汾??top??????????
????select top num * from tablename where ..........
?????塢MONGODB??????????
????mongoDB????????????limit()??skip()??sort()???????????????з???????
??????skip????????????????????????
????page1 = db.things.find().limit(20)
????page2 = db.things.find().skip(20).limit(20)
????page3 = db.things.find().skip(40).limit(20)
????find(???????)??skip???????????????????limit(?????????????)??sort(????????):sort({"age":1})1--????-1--????
????MySQL???mongodb??
?????????
????MySQL:SELECT * FROM user
????Mongo: db.user.find()
????MySQL:SELECT * FROM user WHERE name = 'starlee'
????Mongo: db.user.find({'name' : 'starlee'})
????????
????MySQL:INSERT INOT user (`name`?? `age`) values ('starlee'??25)
????Mongo:db.user.insert({'name' : 'starlee'?? 'age' : 25})
?????????
????MySQL:DELETE * FROM user
????Mongo:db.user.remove({})
????MySQL:DELETE FROM user WHERE age < 30
????Mongo:db.user.remove({'age' : {$lt : 30}})
????????:
MySQL:UPDATE user SET `age` = 36 WHERE `name` = 'starlee'
Mongo:db.user.update({'name' : 'starlee'}?? {$set : {'age' : 36}})
MySQL:UPDATE user SET `age` = `age` + 3 WHERE `name` = 'starlee'
Mongo:db.user.update({'name' : 'starlee'}?? {$inc : {'age' : 3}})
==============others=======================
MySQL:SELECT COUNT(*) FROM user WHERE `name` = 'starlee'
Mongo:db.user.find({'name' : 'starlee'}).count()
MySQL:SELECT * FROM user limit 10??20
Mongo:db.user.find().skip(10).limit(20)
MySQL:SELECT * FROM user WHERE `age` IN (25?? 35??45)
Mongo:db.user.find({'age' : {$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})