当前位置:网站首页>Summary of database 2
Summary of database 2
2022-07-04 15:48:00 【rushduckxzr】
1.JDBC
Use of transmitter PreparedStatement Preprocessing statement , Can prevent sql Inject , Its preprogrammed performance is high . Security , Efficient ,sql concise
Statement: The parent interface ,sql Manual splicing parameters are required .
2.Maven
- development tool : The front end uses HBuilderX, The back end uses eclipse/idea
- project management : The front end uses npm、webpack, The back end uses Maven、SpringBoot
- web middleware : The front end uses NodeJS, The back end uses Tomcat
maven: download , management , compile jar package
A classic business request process :
front end html Page launch ajax request (http://localhost:8080/factoryController/findAll), visit SpringMVC Framework of the Controller Control layer ,SpringMVC Framework resolution request , Find one to call Controller, Find one findAll Method , At the same time, the parameters submitted by the request are encapsulated in java In the object . after Controller The layer passes the request to Spring Framework of the Service The business layer ,Service The layer is passing the request to Mybatis Framework of the Mapper Persistence layer ,Mapper visit MySQL Database queries database tables , The query result is returned to Mapper layer ,Mapper Return to Service layer ,Service Return to Controller layer .Controller hold java Data to json character string , Return to ajax call ,ajax Make a callback and put json String conversion to js object , In the page, you can pass js/vue analysis js object , Finally, show the data to html On the page .
Four characteristics :
1.reposity: Local repository , Create your own folder , For storage maven Download it from the image jar package
2. coordinate :
coordirate, For storing and searching jar The location of the package
groupId: Usually the company's domain name
artifactid: project id, Usually the name of the project
3. rely on : You can specify what you want <dependeneies/> Download the image warehouse to the local warehouse .
4. command : Common commands :
- clean Clean cache
- package pack jar、war
- install install jar To the local warehouse
3.IDEA plug-in unit
1.lombok:@Data: Act on a class , Is a collection of the following annotations :@ToString @EqualsAndHashCode @Getter @Setter @RequiredArgsConstructor
2.SpringBoot Thermal deployment : Changed the code , You don't have to restart , Just recompile to access the new data .SpringBoot The core mechanism : " Open the box " Just import specific jar Package file You can use the functions directly The root cause : SpringBoot It's a simplification of the framework , It's expanded internally , No programmer required .
4.json
JSON refer to JavaScript Object notation , A lightweight data exchange format
Send data to the server : take JS Conversion of objects JSON character string JSON.stringify(Js object )
Accept data from the server : JSON String to JS object JSON.parse("json character string ")
5. Database optimization
1. Use the field name in select Instead of *
2.where Use in and Instead of or
3. Use as much as possible varchar Instead of char, Use numbers instead of string types
4. The return value of the query should not be large
5. Build indexes to improve query efficiency
6.where Try not to use <> or != The operator
7. Optimize like sentence : Fuzzy queries are best started with certain characters
8. Batch insertion performance improvement
9. duplicate removal distinct Filter fewer fields
6.vue
1.vue Of ajax: Asynchronous access , Partial refresh
2.axios The request header Content-Type The default is application/json, and postman The default is application/x-www-form-urlencoded.
ajax/postman It is generally used @RequestParam Receiving parameters :
axiso use @RequestBody Of json Mode to receive parameters :@RequestBody, Will the incoming json Convert string to Json object
3.Vue Why is this called a framework : Applied to Observer mode : The observer pattern defines a one to many dependency , Let multiple observer objects listen to a target object at the same time , When the state of the target object changes , All observer objects will be notified , Enable them to update automatically .
边栏推荐
- web聊天室实现
- Numpy notes
- c# 实现定义一套中间SQL可以跨库执行的SQL语句
- What is the future of the booming intelligent Internet of things (aiot) in recent years?
- Understand the context in go language in an article
- 函数式接口,方法引用,Lambda实现的List集合排序小工具
- 31年前的Beyond演唱会,是如何超清修复的?
- MySQL学习笔记——数据类型(2)
- Data Lake Governance: advantages, challenges and entry
- odoo数据库主控密码采用什么加密算法?
猜你喜欢
Live broadcast preview | PostgreSQL kernel Interpretation Series II: PostgreSQL architecture
What is the future of the booming intelligent Internet of things (aiot) in recent years?
I plan to teach myself some programming and want to work as a part-time programmer. I want to ask which programmer has a simple part-time platform list and doesn't investigate the degree of the receiv
Huawei cloud database DDS products are deeply enabled
Preliminary exploration of flask: WSGI
.Net 应用考虑x64生成
Go zero micro service practical series (IX. ultimate optimization of seckill performance)
Deep learning network regularization
从0到1建设智能灰度数据体系:以vivo游戏中心为例
这几年爆火的智能物联网(AIoT),到底前景如何?
随机推荐
go-zero微服务实战系列(九、极致优化秒杀性能)
Unity script API - time class
Unity脚本API—Component组件
进制形式
31年前的Beyond演唱会,是如何超清修复的?
基于MAX31865的温度控制系统
左右对齐!
Redis' optimistic lock and pessimistic lock for solving transaction conflicts
How did the beyond concert 31 years ago get super clean and repaired?
一篇文章搞懂Go语言中的Context
Decimal, exponential
Rearrange array
每周招聘|高级DBA年薪49+,机会越多,成功越近!
%s格式符
Unity script API - GameObject game object, object object
Go zero micro service practical series (IX. ultimate optimization of seckill performance)
Preliminary exploration of flask: WSGI
What is the future of the booming intelligent Internet of things (aiot) in recent years?
Deep learning neural network case (handwritten digit recognition)
压力、焦虑还是抑郁? 正确诊断再治疗