MySQL

1,mysql default Idle 8 hours, the database will be disconnected, to resolve this problem, you need to increase the length of time 2, modify the MySQL configuration file/etc/mysql/my.cnf, remember to back up before modifying Add the following, if any,

Direct copy of database filesDirect copy of database files is generally the use of the file system Backup tool CP, suitable for small databases, is the most reliable.When you copy a database file, you must ensure that the table is not in use. If the

The recent use of MySQL database is a bit higher than the version encountered, insert and modify statements such as failure conditions. The statement has no errors, but Workbench prompts Field ' id ' doesn ' t has a default value. Reason isThe

MySQL installation process is relatively simple, here is not elaborated, I want to say the question is, about the installation of the Code,When the installation arrives ' Please select the default character set ', choose ' Manul selected default

Amoeba version: 5.1.45-mysql-amoeba-proxy-2.2.0 Source distributionMaster: 192.168.204.128From: 192.168.204.129amoeba:192.168.204.130Dbservers.xml file:650) this.width=650; "src="

purpose : Periodically dump the MySQL database, keeping only the last 5 days of backupOperation Steps :1. Create a new user test password dedicated to backup test123;>grant select,show view,trigger,alter On * * to [email protected] ' localhost '

Packagelianxi1;Importjava.sql.Connection;Importjava.sql.PreparedStatement;ImportJava.sql.ResultSet;ImportJava.sql.ResultSetMetaData;ImportJava.util.HashMap;ImportJava.util.Map;Importorg.junit.Test; Public classjdbctest {@Test Public voidTestmysql ()

Because there are too many classifications, it is not possible to replicate one by one and import categorical data into Ecshop'sThe Ecs_category table. 1. Make the same structure as the Ecs_catergory table data, and encounter problems in this

MySQL each storage engine uses three types (levels) of locking mechanisms: row-level locking, page-level locking, and table-level lockingAvailabilityRow-level locking (Row-level)The most important feature of row-level locking is that the particle

Async.auto ({transaction:function (next) {user.query (' BEGIN ', next);  }, User: [' Transaction ', function (next) {User.findone (Req.param (' id ')). exec (next);    }],//Other queries in the transaction//...}, function (err, results) {if (err)

1, sub-database sub-tableObviously, a main table (that is, very important tables, such as user tables) unlimited growth is bound to seriously affect performance, sub-library and sub-table is a very good solution, that is, the performance

Application optimization1. Using connection pooling2. Reduce access to MySQL1) Avoid repeating queries on the same data2) using query caching3) Add the cache layerSuch as: Extract part of the data from the database and put it on the

1. Download the databaseMysqldump db_name-h 192.168.5.162-uroot-p >/var/www/db_name.sql (this can be customized)2. Download a table in the database:mysqldump db_name table_name-h 192.168.5.162-uroot-p >/var/www/table_name.sql3. Import the imported

First, the operating environmentHuawei Cloud Services Centos 6.5_64bit Minimized installation Intranet IP : 10.124.156.237Mysql-5.6.20.tar.gz Ii. source code compilation and installation process1. Construction of basic

7. mysql-cluster-Installation This article describes how to install Mysql-Cluster. First, let's take a look at the following: (linux User, debian myself) MySQL Cluster is a technology that allows you to deploy the "in memory" Database Cluster in a

Solution to 1366 errors in mysql Recently, I made a project for the school. oracle is used for the database. If oracle is installed in windows, it is relatively simple, but unfortunately, before I took over the project, I just switched to Mac, so

MySQL self-study (8)  2. String functions (1) functions for calculating the number of character strings and functions for String Length CHAR_LENGTH (str) returns the number of characters contained in the str string. A multi-byte character is counted

MySQL slow Query Slow query (slow log)It can help us locate specific SQL statements for SQL statement optimization. For example, slow query logs record the SQL statements whose execution time exceeds the given value, so as to locate the

Mysql usage SummaryDatabase Management System (DBMS) DBMS, Database Management System Database Management, Simply put: is to manage a dataLarge software. DBMS manages and maintains data, or processes data security and integrity. Common DBMS systems:

MySQL (7)1. mathematical functions (1) absolute value function (ABS (x) and return the circumference rate function PI ABS (X) returns the absolute value of X Select abs (2), abs (-3.3), abs (1-9 ); Select pi (); (2) square root function SQRT (x) and