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brief introduction This article is a learning instance of. net mvc + Dapper. There is a link to the source code of the instance. Why write this article Because I don't like EF's bloated and Linq's awkward, I used my own lightweight orm in previous projects. In thinking about and drawing on other ORM frameworks, Dapper found ...

Today, let's take a relatively simple case of SQL optimization to analyze a problem developers often find confusing - slowing down SQL due to view merging For example: A maintenance person (in this case, maintenance refers to slightly modifying an existing system) Due to business changes, a condition has been added to the original SQL. As a re ...

Building tables CREATE TABLE `user` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `name` varchar(10) DEFAULT NULL, `sex` tinyint(1) DEFAULT NULL, `age` tinyint(2) DEFAULT NULL, PRIMARY KEY (`id`), KEY `Index_user` (`name`,`age`) USING BTREE ) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8mb4; Test sql First kind mysql> ...

Recently, there is a need to synchronize the data in a table in mysql to es. After analysis, use the jdbc plug-in of logstash or get the data in mysql. output to es. There are two collection situations: first, full collection, then incremental collection. Process verified as follows: 1. Install longstash and mysql The installation of mysql and ...

Reference resources: https://www.jb51.net/article/115422.htm 1) operate in the CentOS7 environment, create the folder mymy, and create a new file Dockerfile, setup.sh, schema.sql, privileges.sql mkdir mymy cd mymy touch Dockerfile touch setup.sh touch schema.sql touch privileges.sql Dockerfile: FROM mysql:5.7 ENV MYSQL_ALLOW_EMPTY_P ...

Preface I'm going to take you through a new way to understand what interface polymorphism is. Many people, including me, feel helpless when they first learn this thing. They can't understand it. They can't understand it. They just know how to write interfaces, and then they won't be useful. I'll show you how to understand the interface through ...

Extension refers to adding functions not provided by general Mapper. Give an example: An example of using bulk insert as an extension function in the official document of general Mapper is:   tk.mybatis.Mapper.additional.insert.insertlistmapper < T >   tk.mybatis.mapper.additional.insert.InsertListProvider Let's ...

From: http://www.maomao365.com/?p=10564 Abstract: The following describes how to keep only one piece of data when MySQL database queries duplicate dataImplementation ideas: There is no row Ou number function in MySQL database, so we need to change direction to implement this function.  --1.View basic data table mysql> select * from ...

concept   Nonpartitioned tables can be moved as an online operation without blocking any concurrent DML operations. A table move operation now also supports automatic index maintenance as part of the move. Non partitioned tables can be moved as online operations without blocking any concurrent DML operations. A table move ope ...

   this article takes the initial EMP table of SCOTT users as a reference. The code can be used directly. The statement to query the structure of the EMP table is as follows, code 1: DESC EMP; The structure of EMP table is as follows: [result 1]: SQL> DESC EMP; //Is the name empty? Type -------------------------- ...