Abnormal phenomenon
Recently, the project needs to use Debezium to specify the binlog location to read data. When FileDatabaseHistory is configured to save offset, an unrecognized schema exception will appear.
14:52:18.237 [blc-9.135.12.10:3307] ERROR io.debezium.connector.mysql.MySqlStreamingChangeEventSource - Encountered change event ' ...
Posted by jasonscherer on Wed, 18 May 2022 01:40:00 +0300
Cache mechanism under Mybatis concurrency
Mybatis level 1 and level 2 cache
Level 1 cache: It is enabled by default. For multiple identical operations in a session, only the first time will go to the database to query, and then directly go to the cache to get the data! 1. Query the record for the first time, and write the queried data into th ...
Posted by miramichiphoto on Mon, 16 May 2022 18:49:30 +0300
Database DB
The database itself supports concurrent network operations
Using database to add, delete, check and modify data is more efficient than storing data in files
Each folder is a database
Database management system DBMS: sqlserver MySQL Oracle
install
Download: https://downloads.mysql.com/archives/community/ Select the version and ...
Posted by osiris1603 on Mon, 16 May 2022 17:00:40 +0300
Review the previous: Learn the explain tool of MySQL
(at the same time, it is emphasized again that these articles on MySQL are based on version 5.7, and the relevant conclusions and conclusions are not necessarily applicable to other versions)
MySQL official documents( https://dev.mysql.com/doc/refman/5.7/en/optimization-indexes.html )There is ...
Posted by jamkelvl on Mon, 16 May 2022 11:45:34 +0300
preface
Why study MySQL? Because MySQL is one of the most popular relational database management systems, MySQL is the best software in web applications. The sql language used by MySQL is the most commonly used standardized language for accessing databases.
Rest assured, friends who read this issue are suitable for: website development, softwar ...
Posted by keigowei on Mon, 16 May 2022 11:38:44 +0300
Reading suggestions
This is HTTP 2 0 series, the author recommends reading in the following order:
HTTP request in Go -- http1 1 request process analysis
Go launched http2 0 request process analysis (previous)
Go launched http2 0 request flow analysis (Part 2) -- data frame & flow control
review
In the previous article (* http2clientco ...
Posted by brandone on Mon, 16 May 2022 09:17:40 +0300
SQL statement
Query statement select
SELECT column_name,column_name
FROM table_name
[WHERE Clause]
[LIMIT N][ OFFSET M]
select is a query statement, followed by commas to separate multiple columns, and * indicates all columns
Which form is it from after from
where add conditional restrictions
Limit limit the number of displays
Offset indic ...
Posted by Sgarissta on Mon, 16 May 2022 03:42:58 +0300
Operating environment:
Development tools: IDEA /Eclipse Database: mysql5 seven Application service: Tomcat7/Tomcat8 Using the framework springboot+vue
Project introduction
For the design of the ordering platform website, the system development mainly adopts java language technology and applies MySQL database to complete data storage in the d ...
Posted by drums on Sat, 14 May 2022 22:16:22 +0300
introduction
The framework without model is not flexible! Each framework will carry out in-depth design for the database,
In order to quickly add, delete, modify and check SQL, abstract the repeated work and improve the efficiency of application development.
In this issue, we will talk about the initial use of laravel's model.
Code time
The mo ...
Posted by verano on Sat, 14 May 2022 06:02:55 +0300
Interface oriented programming
Programming steps
Get connection
Before that, to obtain the mysql driver, you need to put the corresponding jar package under the project:
Mode 1
import org.junit.Test;
import java.sql.Connection;
import java.sql.Driver;
import java.sql.SQLException;
import java.util.Properties;
public class Connectio ...
Posted by toysrfive on Fri, 13 May 2022 08:40:54 +0300