Tag:Relation

  • Design pattern learning 02 (Java implementation) — UML diagram and class diagram representation

    Time:2021-6-23

    Write on the front Take notes on learning design patterns Improve the flexible use of design patterns Learning address https://www.bilibili.com/vide… https://www.bilibili.com/vide… Reference article http://c.biancheng.net/view/1… Project source codehttps://gitee.com/zhuang-kang/DesignPattern 2. UML diagram Unified Modeling Language (UML) is a visual modeling language for software design. Its characteristics are simple, unified, graphical, and can express the dynamic and static […]

  • Online examination system (vue2 + elementui + express4 + mongodb)

    Time:2021-6-23

    This is my graduation project, from 0 to 1, the front and back of the independent development completed. Function is not much, record here, review the old and know the new! Project GitHub address:https://github.com/FinGet/Exam, blog address:https://finget.github.io/ Update record: April 9, 2018, MD5 encryption Install mongodb To install mongodb under windows, please refer to my blog:Installing […]

  • Flink’s practice in vipshop

    Time:2021-6-18

    Introduction:Flink’s containerization practice and product experience in vipshop. Since 2017, vipshop has built a high-performance, stable, reliable and easy-to-use real-time computing platform based on k8s to support the smooth operation of vipshop’s internal business in peacetime and greatly promoted. The current platform supports mainstream frameworks such as Flink, spark and storm. This article mainly shares […]

  • Design of multiple login users in ABP

    Time:2021-6-14

    scene In the “school management system”, students, parents, teachers, educational administration may log in and do some of their own operations. These users need different attributes. For example, students have student numbers, but teachers don’t. Application users When coding, you often need to get the information of the current login user, which is the application […]

  • Flink multi stream join

    Time:2021-6-14

    Multi stream join The semantics of real-time calculation join is consistent with that of traditional batch join, which is used to connect two tables. The difference is that the real-time calculation is related to two dynamic tables, and the result of the connection will be updated dynamically to ensure the consistency between the final result […]

  • Imitate Kafka and realize MQ from scratch

    Time:2021-6-7

    Imitating Kafka, MQ is implemented from scratch, and 80% of the basic functions in Kafka are realized. If you only read articles and source code when learning Kafka, you may forget it soon. You’d better implement a “simplified version” of Kafka yourself, Overview of implementation functions 1. Implementation of production and consumption API based on […]

  • (3) Orm of Django web development

    Time:2021-6-5

    Orm in Django Object relational mapping (ORM) is to automatically persist objects in object-oriented language programs to relational databases by using metadata describing the mapping between objects and databases. Reference documents:https://docs.djangoproject.co… Django database configuration #Settings file DATABASES = { “default”: { “Engine”: “Django. DB. Backends. MySQL”, which can be modified according to the actual situation, […]

  • The child properties of the left table of yii2 connection are not displayed

    Time:2021-5-29

    When multiple tables are associated, the association is done well, that is, the fields of sub tables are not displayed, //Controller I thought this would be OK, but I made a mistake Undefined index: testid Later changed to //Controller In this way, it can be displayed without error. This work adoptsCC agreementReprint must indicate the […]

  • Quick reference table of laravel eloquent Model Association

    Time:2021-5-29

    A quick list of laravel’s eloquent ORM 5.5 One to one connection Presentation details: In this presentation, we have two models (owner and car) and two tables (owners and cars). Business logic: A user can own a car\A car can have an owner. Association diagram: Related details: The cars table must store the owner ID. […]

  • IOS bottom layer exploration – class expansion and associated objects

    Time:2021-5-29

    IOS bottom Exploration Series IOS bottom layer exploration – alloc & init Exploration of IOS bottom layer – calloc and ISA IOS bottom layer exploration – class IOS bottom layer exploration cache_ t IOS bottom layer exploration method IOS bottom layer exploration – message search IOS bottom layer exploration – message forwarding IOS bottom layer […]

  • Most complete Django explanation, zero basis, from introduction to mastery (NO2 — model)

    Time:2021-5-13

    The text and pictures of this article are from the Internet, only for learning and communication, and do not have any commercial use. The copyright belongs to the original author. If you have any questions, please contact us in time The following article comes from Tencent cloud Author: Python advanced (want to learn Python? Python […]

  • Three steps of SQL optimization

    Time:2021-5-10

    One day, the development students reported that there was a very full SQL in the online business database, and it took almost one minute to finish each time. I hope we can help optimize it. The specific SQL is as follows: SQL optimization step 1 – view execution plan For a SQL optimization, our first […]