Programmer Think

Main technical implementation: spring, springmvc, springboot, springboot security permission control, mybatis, session, jquery, md5, bootstart JS, tomcat, interceptor, etc. Main functions: login, user management, role authority management, menu management, department management, luggage cabinet management, user deposit management, record que ...

1. Insert or replace If we want to INSERT a new record (INSERT), but if the record already exists, delete the original record first and then INSERT a new record. Scenario example: the latest transaction order information of each customer stored in this table is required to ensure that the data of a single user is not entered repeatedly, with ...

ALTER keyword usage -- Add field action alter table tbl_name add Field name field type[Integrity constraints] [first|after Field name] -- Add user name field ALTER TABLE user1 ADD username VARCHAR(20); -- Add password field ALTER TABLE user1 ADD password CHAR(32) NOT NULL; -- Add mailbox field ALTER TABLE user1 ADD email VARCHAR(50) NOT NUL ...

Recently, I received a request that users can apply to create one or more docker containers. The containers should always exist, users can access them no matter how long it takes, and the data generated by users always exists. In other words, we should achieve container persistence, that is, we should provide a small server, However, over time, ...

1. Installation environment linux: centos 7.9 MySQL: 8.0.23 Installation directory: / opt/mysql (any directory can be used) Attach the download address of MySQL official website: https://dev.mysql.com/downloads/mysql/5.7.html#downloads , the interface after entering is as follows. Click the "Archives" tab to select different version ...

Preparation before learning: first create two tables for sentence experiment mysql -uroot -p show databases; create database plane; use plane; create table destination ( region char(20), place_name char(20)); insert into destination values('southwest','chengdu'); insert into destination values('north China','beijing'); insert into destinat ...

catalogue 1, Prerequisites for database programming 2, Database programming in Java: JDBC 3, How JDBC works 4, Construction of development environment 5, JDBC programming in MySQL 1. Five step process 2. Add information 3. Query information 4. Delete information 5. Modify information 1, Prerequisites for database programming Pro ...

catalogue Overall outline The first intimate contact with MySQL, why learn database? Related concepts of database Characteristics of database storage data MySQL software Classification of SQL language Database data table file required later MySQL database Overall outline First intimate contact with MySQL Why study databases?       ...

Research significance: With the development of information technology and the rapid rise of Internet economy, online shopping has attracted more and more attention. The online wholesale market model of vegetables and fruits is bound to become a part of its trend. The fruit online wholesale system based on springboot} technology carries out t ...

1, Environmental preparation Existing environment: mysql8.0.25 nacos resources Resource nameaddressexplainnacoshttps://github.com/alibaba/nacos/tagsService discovery, registry, configuration centerseata1.4.2https://seata.io/zh-cn/blog/download.htmlDistributed transaction Introduction to Seata 2, seata AT mode integration 1. nacos configur ...