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preface It was in 2002, and MySQL 4.1 began to support UTF-8 coding RFC 2279 It is stipulated that the code uses 1 ~ 6 bytes to store a single character, and MySQL developers checked it in September of the same year Source code The UTF-8 encoding is changed from the maximum 6 bytes to 3 bytes, so there is the current UTF8MB3. As we all know, U ...

@Go MySQL transfer of data real-time incremental synchronization tool: https://blog.csdn.net/weixin_...Installation, configuration and Kibana foundation of Elasticsearch notes: https://blog.csdn.net/weixin_...Go MySQL transfer official Manual: https://www.kancloud.cn/wj596...Environment installation of GO notes: https://blog.csdn.net/weixin_... ...

Using amoeba to separate mysql reading and writing 1. What is amoeba? Amoeba (amoeba) project focuses on the development of distributed database proxy. Located between Client and DB Server(s). Transparent to clients. It has load balancing, high availability, sql filtering, separation of reading and writing, routing related queries to the targ ...

JDBC (Java database connectivity) Is a Java API for executing SQL statements, which can provide unified access to a variety of relational databases. It is composed of a group of classes and interfaces written in Java language. JDBC provides a benchmark, according to which more advanced tools and interfaces can be built, so that database develo ...

Resource download: https://download.csdn.net/download/weixin_44893902/45603787 Exercise point design: fuzzy query, delete, add, modify 1, Language and environment Implementation language: JAVA language.Environment requirements: MyEclipse/Eclipse + Tomcat + MySql.Use technology: Jsp+Servlet+JavaBean or spring MVC + Spring + mybatis. 2 ...

flyway is a database migration tool that supports automatic backup and execution of SQL scripts. It is very convenient for us to deploy applications to multiple environments to initialize databases or upgrade database tables. 1, Why use flyway Let's make an analogy with the Git version control tool, which is often used now. It can well ...

Environmental preparation CREATE TABLE `emp` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(100) NOT NULL, `age` int(3) NOT NULL, `salary` int(11) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4; insert into `emp` (`id`, `name`, `age`, `salary`) values('1','Tom','25','2300'); insert into `emp` (`id` ...

catalogue alias            Subquery exists join query view ​ combine case Date time function Null and no values regexp regular expression   stored procedure deadlock         Common error codes alias            ...

1. Introduction to SQL join multi table connection SQL Join clause is mainly used in select statements to combine the rows of two or more tables, query based on the common field (often id field) between these tables, and return all rows that meet the conditions from multiple tables. 2. Common join clause types Common join clause types include I ...

1: Overview          MyBatis is an excellent persistence layer framework that supports common SQL queries, stored procedures and advanced mapping. MyBatis eliminates almost all the manual setting of JDBC code and parameters and the retrieval of result sets. MyBatis uses simple XML or annotations for con ...