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What is business Transaction is to operate multiple sql statements. These sql statements must be executed successfully at the same time. If one fails, it will return to its original state Role of transaction Ensure the security of data, if transfer between banks Four characteristics of transaction ACID atomic ...

First of all, consider using cache for processing. If the cache is not enough, then use read-write separation for implementation application.yml configures two data sources #Default usage configuration spring: profiles: active: dev --- #Development and configuration spring: profiles: dev datasource: master: jdbc-url: jdbc: ...

Create a database first CREATE TABLE user (   id varchar(32) CHARACTER SET utf8 NOT NULL,   name varchar(50) CHARACTER SET utf8 DEFAULT NULL ,   dflag char(1) CHARACTER SET utf8 DEFAULT NULL ,   PRIMARY KEY (`id`) ) jdbc.properties configuration mysql.driver=com.mysql.jdbc.Driver mysql.url=jdbc:mysql://127.0.0.1:3306/qingmu?char ...

LNMP represents the web server architecture of Nginx+MySQL+PHP under Linux system. Linux is a kind of Unix computer operating system, which is the most popular free operating system. Representative versions include debian, centos, ubuntu, fedora, gentoo, etc. Nginx is a high-performance HTTP and reverse proxy server, and also an IMAP/POP3/SMTP ...

1. Startup is the way to create bean s pom.xml <dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.10</version> </dependency> <!-- maven Not in the warehouse oracle Database driver, here jar Put it under the project for i ...

Catalog brief introduction install Component Simple use Execute native sql (not commonly used) orm use (key) Common data types Common parameters of Column Common operations (CURD) Create an instance of a mapping class Create Session session add()/ ...

PT OSC execution log In the DROP COLUMN operation for table tb004 with data volume of 100000, the PT OSC tool log is: Operation, tries, wait: analyze_table, 10, 1 copy_rows, 10, 0.25 create_triggers, 10, 1 drop_triggers, 10, 1 swap_tables, 10, 1 update_foreign_keys, 10, 1 Altering `db001`.`tb004`... Creating new table... ...

Recently, we need to cache the data in mysql table into redis, and the list display also needs to use paging to query. At first, we thought that HASH structure can meet the needs, and then we can use ZSET and HASH structure to store data to realize redis paging. The steps are as follows: 1. First, use ZSET to store the id in table A in the form ...

Reason: when using the spring datajpa statement to query the null value of a field in the database table, such as:findByIdAndNameIsNullfindByIdAndNameIsNotNullWhen the value of name is empty string, the result of query is very different 1. Build tables CREATE TABLE `user` ( `id` bigint(11) NOT NULL AUTO_INCREMENT, `name` varchar(45) CHARAC ...

Tuesday, 08. October 2019 11:01 am Initial preparation: 1. jdk installation Do the following on all three machines (depending on the number of machines you have): 1) you can install jdk through apt get, execute whereis java on the command line to get the installation path of java, or download the installation package of jdk manually f ...