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Basic steps for JPA to access database: 1. Define the Table in the Entity class mapping database. The key is @ Entity, @ Table annotation Entity class, @ Entity annotation marks the Entity class of JPA, @ Table annotation indicates which Table in the database corresponds to the Entity class. @The Id a ...

https://blog.csdn.net/littlely_ll/article/details/82706874 1. in storage import datetime import pandas as pd import sqlalchemy from sqlalchemy import create_engine from sqlalchemy.sql import text, func from sqlalchemy.orm import sessionmaker,relationship from sqlalchemy.ext.declarative import decla ...

Preface Before introducing a technology, it must be clear what problems the technology can solve for the project. Before I understood message queue, I thought that message queue was mainly used to send messages such as SMS and email (asynchronous decoupling), but I found my understanding was wrong on ...

cause A field of online data is empty, which is calculated by running and saving (low voice force: using saved data is really unfriendly). process View stored procedure logic Call the stored value through parameter test to check whether there is return value. There is no problem with the stored val ...

This article starts with WeChat official account of vivo Internet technology.Links: https://mp.weixin.qq.com/s/l4vuYpNRjKxQRkRTDhyg2QAuthor: Chen wangrong Distributed task scheduling framework is almost a necessary tool for every large-scale application. This paper introduces the demand background and pain points of the use of task schedu ...

1, Theoretical basis 1.1 front end optimization Use dynamic and static separation to store static resources in a third-party file server to achieve cdn acceleration, so as to reduce the bandwidth of second kill and rush to buy When the user clicks the seckill button, the button should be disable ...

Source code analysis Because spring security social is implemented based on social authentication filter, let's start with social authentication filter When it comes to Filter, there must be a corresponding configuration class SocialAuthenticationFilter is no exception. Its corresponding configuration class is SpringSocialConfigurer. To make ...

1.3 first hibernate program (IDEA+Maven+Hibernate) 1.3.1 create project 1. Create a Maven project first .2. Improve the project We need to create the successful project directory structure manually. Create the java and resources folders in the main directory.       &em ...

1. JPA understanding JPA is the abbreviation of Java Persistence API. It is a Java EE 5.0 platform standard open source object relationship mapping (ORM) specification developed by Sun company on the basis of fully absorbing the existing ORM framework (Hibernate). The relationship between Hibernate and JPA: Hibernate is an open-source object re ...

Mybatis source code analysis I (initialization process) Recently, I learned the source part of mybatis. Now I am going to record my understanding process while learning. This article mainly records the initial process of mybatis, mainly including the following points: 1. What did initialization do 2. How to parse the parameters of mybatis-confi ...