MySQL " replace in " pit self-increasing id, ready for opportunities to have problems, this problem will not appear on MySQL 5.7.17

MySQL "replace in" pit self-increasing id, ready for opportunities to have problems, this problem will not appear on MySQL 5.7.17The following is online information.Source: http://www.cnblogs.com/monian/archive/2014/10/09/4013784.htmlMySQL "replace in" pitMySQL has many extensions to SQL, some of which are convenient to use, ...

Posted by dyip on Tue, 25 Dec 2018 11:06:06 -0800

Using mysq Connector/C to connect mysql server process under linux

Write on the front: I found a lot of information on the Internet, most of them are directly installed MySQL library, implicitly calling MySQL lib library and mysql.h header file. When the server can not install mysql, but need to communicate with the server with Mysql, you can use the following methods. Download mysql-connector-c-6.1.11-linu ...

Posted by webster08 on Sun, 23 Dec 2018 22:36:06 -0800

Understanding and configuring Out of memory: Kill process

Change from: Love is open source Understanding OOM killer Recently, one VPS customer complained about MySQL hanging up for no reason, and another complained that VPS often crashed. It is a common Out of Memory problem to log on to the terminal and look at it. This is usually due to the lack of system memory caused by a large number of memory ...

Posted by bhavin12300 on Sun, 23 Dec 2018 11:33:05 -0800

MySQL Learning Notes - DQL, DML, DDL, TCL statements, constraints (primary and foreign keys)

MySQL Using tools Command Line Windows MySQL Front I. Common MySQL Data Types 1. char Occupied byte number char(n) Fixed length string, fixed size storage control For example: char(2) 2. varchar Occupied byte number varchar(n) Variable length string, storage space equal to actual data space A string co ...

Posted by racing_fire on Sat, 22 Dec 2018 22:03:06 -0800

Spring Boot and Kotlin use JdbcTemplate to connect MySQL

Some examples of the Web tier were introduced, including building RESTful API s and rendering Web views using Thymeleaf template engine, but these are not enough to build a dynamic application. Usually we do App or Web applications, we need content. Content is usually stored in various types of databases. After receiving the access request, the ...

Posted by phpknight on Sat, 22 Dec 2018 21:57:06 -0800

MySQL saves emoji expressions with the Linux settings database code utf8mb4

1. Background of the problem: When MySQL database is coded utf8, saving emoji expression fails, and abnormal information: java.sql.SQLException: Incorrect string value: '\xF0\x9F\x92\x94' for column 'content' at row 1 View the database character set information as follows mysql> SHOW VARIABLES WHERE Variable_name LIKE 'c ...

Posted by validkeys on Sat, 22 Dec 2018 07:33:05 -0800

CentOS+Docker+Mysql+Gerrit+Nginx configuration

Software environment: CentOS 7.0 Docker 18.06.0-ce Following is the docker image Mysql 5.7 Gerrit 2.15.3 Nginx 1.15.2-alpine Assume that the current server ip address is (all three software are on the same server) 192.168.0.1 Note: When using docker image, it is strongly recommended to fix the mirror version number o ...

Posted by voltrader on Fri, 21 Dec 2018 21:51:05 -0800

No operations allowed after connection close error occurred in Spring Book environment

Spring Cloud + Spring MVC + Spring Data JPA + MySql + Postgresql Among them, the project is equipped with multiple data sources, and there is no problem in the early development test, but when the project is tested on the server, the next morning there is an abnormal database connection. After checking the log, the following ex ...

Posted by successor on Thu, 20 Dec 2018 09:15:05 -0800

java jdbc curd && learning document [translation]

jdbc tutorial https://www.tutorialspoint.com/jdbc/jdbc-sample-code.htm (English) http://www.yiibai.com/jdbc/jdbc-sample-code.html#article-start (Chinese) jdbc curd example http://www.codejava.net/java-se/jdbc/jdbc-tutorial-sql-insert-select-update-and-delete-examples (English) http://www.cnblogs.com/sbj-dawn/p/7111990.html (Chinese) 2 Crea ...

Posted by TwistedLogix on Thu, 20 Dec 2018 02:24:04 -0800

ssm project uses Mybatis dynamic splicing sql statements, the generated sql Chinese is displayed as??? Questions (Chinese parsing of configuration file sql statements)

Scene reappearance There is a table. Now we want to query whether a character field in the table contains some keywords. Example: there is a field tag in the table; now it is to determine whether the tag contains keywords, the number of keywords is uncertain, so we need to use dynamic sql statements to splice, and screen out tags that cont ...

Posted by alpinec on Wed, 19 Dec 2018 20:18:05 -0800