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Reprint please indicate Original: https://me.csdn.net/jxysgzs 1, Necessary foreword We learned about the basic use of spring datajpa through the previous article. In this article, we will explain the basic addition, deletion, modification and query. After all, CURD operation is essential for every p ...

(1) Object serialization and deserialization 1) Insufficient text saving objects When the attributes of an object change, the number of information writes or reads needs to be increased or decreased; Poor information security; 2) New method of object saving: Use serialization and deserializati ...

The effect of wechat applet 1: Wechat code (2)wxxml <view class="container-body container-gray" style="display:{{showfootertab==0?'block':'none'}}"> <form bindsubmit="evaSubmit"> <view class="group"> <view class="group-header">Problem description</view> <vie ...

Cold and hot backup of database Data export is not exactly equal to data backup: Data export refers to the data in the database is conversed into SQL statements for export, so the export is SQL files. Often used to migrate data from one system to another in order to mask differences between systems Data backup refers to copying the relevant ...

execute(String  sql)    Any sql statement can be executed, but the return value is void, so it is generally used for database creation, modification, deletion and data table record addition, deletion and modification.     int  update(String sql)  int  update(String sql, Object...args) Add, delete, args passes the actual parameter, and retur ...

Operation of database Linked database mysql -u root -proot -- Direct display of password is not recommended mysql -uroot -p Exit database exit/quit The sql statement needs a semicolon at the end; the end Show database version select version(); Display time select now(); View all databases ...

First, a PooledConnection class is created to encapsulate the connection information; package com.bai.pool; import java.sql.Connection; /** * * Copyright: Copyright (c) 2018 LanRu-Caifu * * @ClassName: PooledConnection.java * @Description: Connection information stored in connection pool * * @version: v1.0.0 * @author: Mr ...

order This paper mainly studies the persistence enabled of artemis persistenceEnabled activemq-artemis-2.11.0/artemis-server/src/main/java/org/apache/activemq/artemis/core/config/impl/ConfigurationImpl.java public class ConfigurationImpl implements Configuration, Serializable { //...... private boolean persistenceEnabled = ActiveMQDefau ...

Technology coverage (JavaWeb, HTML, Ajax, JQuery, Bootstrap) When contacting this part of knowledge, we often do some small demos to practice. Inevitably, we need to touch a certain amount of data. We often need to echo the data from the database to the page. However, with the increase of data volume, if we do not deal with the query or displa ...

In the last blog, I simply said what is distributed lock, and built a basic environment (very simple). This blog needs to start to experience distributed lock formally. Because it is developed on a single machine, there is no cluster, but the specific implementation of the code method is no different fr ...