Java combines query operations with connected databases (20.5.29)

IDEA Connect to MySQL Database Add MySQL database connector to project Using mysql-connector-java-8.0.15.jar as an example, add jar files to your project The JDBC-MySQL connector is now added successfully Create the appropriate connection Connect the corresponding class in the jar file try { ...

Posted by pellky on Fri, 29 May 2020 11:57:32 -0700

Build the spring cloud microservice framework: VI. database persistence layer - spring datajpa

Build microservice framework (database persistence layer spring datajpa) Used to Mybatis, this time for a change, integrate spring datajpa in SQuid. Source address: Build microservice framework (database persistence layer spring datajpa) Github address: SQuid introduce I've heard of HibernateJPA before, but I've never used it. Mybatis i ...

Posted by vimukthi on Fri, 29 May 2020 04:31:05 -0700

Database optimization of MySQL

No matter what kind of service, its optimization is nothing more than from two aspects, the first is the optimization of hardware, the second is the optimization of the system and the service itself.1, Query the number of times to connect to the MySQL server mysql> show status like 'connections'; +---------------+-------+ | Variable_name | ...

Posted by tukon on Fri, 29 May 2020 04:14:48 -0700

Linux system CentOS 6.9 x64 configures jdk and MySQL 8.0 environment and grants MySQL remote access

Blogger server version and installed jdk and mysql versions: System: CentOS 6.9 jdk: jdk1.8_221 MySQL: mysql8.0.20 Relevant files needed in the configuration process (click to download from Baidu cloud): jdk: jdk-8u221-linux-x64.tar.gz (extraction code: kkp7) mysql: mysql-8.0.20-1.el6.x86_64.rpm-bundle.tar (extraction code: 0pvh) Softwar ...

Posted by daydreamer on Tue, 26 May 2020 23:56:40 -0700

Introduction to using MySQL's own tools

In MySQL, there are many powerful tools, such as mysql, mysqladmin, mysqldump, etc.1. mysql commandThe Mysql command is the most common command tool used to provide a command line interface for users to operate and manage MySQL servers.You can see how it's used in more detail through mysql --help.1) Grammar used for -e, -u, -p, -h, -P, and so ...

Posted by Spudgun on Tue, 26 May 2020 10:54:08 -0700

Oracle Query_Form Query

Previously, we detailed the changes and additions to Oracle. Today let's go on to learn more about Oracle's queries. Queries in Oracle are a big deal!!! Follow the steps of brilliant sir, move, move ~~   Small bag of knowledge Before that, let's talk about a little bit of Oracle commentary, which is very helpful for our development, oh!!! ...

Posted by boyakasha on Tue, 26 May 2020 10:43:55 -0700

MyBatis code generator - based on Maven plug-in

MBG is the official code generator of MyBatis. MBG can automatically generate entity classes, Mapper interfaces and corresponding XML files, which can reduce the workload of developers to a certain extent. This paper introduces how to use MBG Maven plug-in. 1, In pom files, dependency packages and plug-ins are introduced. <dependency ...

Posted by WormTongue on Tue, 26 May 2020 10:01:20 -0700

[original] CentOS 7 builds multiple instances of MySQL 8 (want to do several)

cause   Recently, the project began to be reconstructed, which may use the situation that the master-slave plus read-write separation. I wanted to build a local one first to try the effect. As a result, baidu found a lot of them, but few of them went to the pit. Most of them were copying other people's content. The key is that there will be e ...

Posted by windjohn on Mon, 25 May 2020 21:57:20 -0700

20. Use and principle of PageHelper paging plug-in

1. Logical paging and physical paging Logical paging: also called memory paging. Logical paging depends on the code written by the programmer. What the database returns is not the paging result, but all the data, which is then passed by the programmer The code obtains the paging data, takes out all the data, first stores it in memory, ...

Posted by ChetUbetcha on Mon, 25 May 2020 20:53:31 -0700

MySQL installation and basic use under Linux

1. MySQL installation (install using yum) yum install mysql* –y Linux MySQL data is stored in / var/lib/mysql by default/ [root@study ~]# cd /var/lib/mysql/ [root@study mysql]# ll //Total consumption 20488 -rw-rw----. 1 mysql mysql 10485760 5 23 23:55 ibdata1 -rw-rw----. 1 mysql mysql 5242880 5 23 23:55 ib_logfile0 -rw-rw----. 1 mysql mysql 5 ...

Posted by Exemption on Sun, 24 May 2020 22:31:29 -0700