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Mongodb与关系型数据库对比

Mongodb与关系型数据库对比
由于之前主要接触的是关系型数据库,所以主要将Mongodb与关系型数据库进行对比:主要从术语、Server与Client、数据定义语言和操作语言四个方面进行比较。

1.术语

Mongodb与关系型数据库的术语对比如下图

关系型数据库术语 MongoDB 术语
database database
table collection
row document or BSON document
column field
index index
table joins embedded documents and linking
primary key Specify any unique column or column combination as primary key. primary key In MongoDB, the primary key is automatically set to the _id field.
aggregation (e.g. group by) aggregation pipeline See the SQL to Aggregation Mapping Chart.

2.数据库Server与Client对比

type MongoDB MySQL Oracle Informix DB2
Database Server mongod mysqld oracle IDS
Database Client mongo mysql sqlplus DB-Access

3.数据定义语言CREATE、ALTER、DROP比较

关系型数据库SQL语句 MongoDB语句
CREATE TABLE users ( id MEDIUMINT NOT NULL AUTO_INCREMENT,user_id Varchar(30),age Number,status char(1),PRIMARY KEY (id)) Implicitly created on first insert() operation. The primary key_id is automatically added if _id field is not specified. db.users.insert( { user_id: "abc123", age: 55, status: "A" } ) However, you can also explicitly create a collection: db.createCollection("users")
ALTER TABLE usersADD join_date DATETIME Collections do not describe or enforce the structure of its documents; i.e. there is no structural alteration at the collection level. However, at the document level, update() operations can add fields to existing documents using the $set operator. db.users.update( { }, { $set: { join_date: new Date() } }, { multi: true })
ALTER TABLE usersDROP COLUMN join_date Collections do not describe or enforce the structure of its documents; i.e. there is no structural alteration at the collection level. However, at the document level, update() operations can remove fields from documents using the $unset operator. db.users.update( { }, { $unset: { join_date: "" } }, { multi: true })
CREATE INDEX idx_user_id_ascON users(user_id) db.users.createIndex( { user_id: 1 } )
CREATE INDEX idx_user_id_asc_age_descON users(user_id, age DESC) db.users.createIndex( { user_id: 1, age: -1 } )
DROP TABLE users db.users.drop()

4.数据操作语言CURD比较

INSERT

SQL INSERT 语句 MongoDB insert语句
INSERT INTO users(user_id,age,status)VALUES ("bcd001",45,"A") db.users.insert( { user_id: "bcd001", age: 45, status: "A" })

SELECT

SQL SELECT 语句 MongoDB find 语句
SELECT *FROM users db.users.find()
SELECT id,user_id,statusFROM users db.users.find( { }, { user_id: 1, status: 1 })
SELECT user_id, status FROM users db.users.find( { }, { user_id: 1, status: 1, _id: 0 })
SELECT *FROM usersWHERE status = "A" db.users.find( { status: "A" })
SELECT user_id, statusFROM usersWHERE status = "A" db.users.find( { status: "A" }, { user_id: 1, status: 1, _id: 0 })
SELECT *FROM usersWHERE status != "A" db.users.find( { status: { $ne: "A" } })
SELECT *FROM usersWHERE status = "A"AND age = 50 db.users.find( { status: "A", age: 50 })
SELECT *FROM usersWHERE status = "A"OR age = 50 db.users.find( { $or: [ { status: "A" } , { age: 50 } ] })
SELECT *FROM usersWHERE age > 25 db.users.find( { age: { $gt: 25 } })
SELECT *FROM usersWHERE age < 25 db.users.find( { age: { $lt: 25 } })
SELECT *FROM usersWHERE age > 25AND age <= 50 db.users.find( { age: { $gt: 25, $lte: 50 } })
SELECT *FROM usersWHERE user_id like "%bc%" db.users.find( { user_id: /bc/ } )
SELECT *FROM usersWHERE user_id like "bc%" db.users.find( { user_id: /^bc/ } )
SELECT *FROM usersWHERE status = "A"ORDER BY user_id ASC db.users.find( { status: "A" } ).sort( { user_id: 1 } )
SELECT *FROM usersWHERE status = "A"ORDER BY user_id DESC db.users.find( { status: "A" } ).sort( { user_id: -1 } )
SELECT COUNT(*)FROM users db.users.count() or db.users.find().count()
SELECT COUNT(user_id)FROM users db.users.count( { user_id: { $exists: true } } ) or db.users.find( { user_id: { $exists: true } } ).count()
SELECT COUNT(*)FROM users WHERE age > 30 db.users.count( { age: { $gt: 30 } } ) or db.users.find( { age: { $gt: 30 } } ).count()
SELECT DISTINCT(status)FROM users db.users.distinct( "status" )
SELECT *FROM usersLIMIT 1 db.users.findOne() or db.users.find().limit(1)
SELECT *FROM usersLIMIT 5SKIP 10 db.users.find().limit(5).skip(10)
EXPLAIN SELECT *FROM usersWHERE status = "A" db.users.find( { status: "A" } ).explain()

UPDATE

SQL Updatey语句 MongoDB update语句
UPDATE usersSET status = "C"WHERE age > 25 db.users.update( { age: { $gt: 25 } }, { $set: { status: "C" } }, { multi: true })
UPDATE usersSET age = age + 3WHERE status = "A" db.users.update( { status: "A" } , { $inc: { age: 3 } }, { multi: true })

DELETE

SQL Delete 语句 MongoDB remove语句
DELETE FROM usersWHERE status = "D" db.users.remove( { status: "D" } )
DELETE FROM users db.users.remove({})

学习资料

网址:

  1. 官方Tutorial
  2. 官方 Document
  3. Tutorial
  4. Java操作Mongodb

Mongodb官方文档感觉写的真心不错,推荐!

posted @ 2016-10-31 09:07  一路向前走  阅读(232)  评论(0编辑  收藏  举报