MySQL

Custom functionsCreating a Custom functionCREATE FUNCTION function_nameRETURNS{STRING | Interger | REAL | DECIMAL}Routine_bodyAbout function bodies The function body consists of a valid SQL statement The function body can be a simple select

The larger the database, the more data in a single table, the query read-write, and the locking mechanism, can cause serious database performance impact.table lock, Row lock, is to ensure the integrity of the data,Sub-tableThe table is a large table,

--Select * FROM (select Nid from Part where nid > 2) as A--Create view V1 as – Create View V1 as #创建视图--Select Man _to_woman.nid,man.name as mname,woman.name as Wname from man_to_woman--left JOIN man on man_to_woman.man_id = man.nid--L EFT JOIN

Original page http://www.web-jia.com/view.php?a=12Today there are some requirements for some data, now this system uses MySQL database, no SQL Server export data is so simpleThe simplest thing to think about data is, of course, to export the

To create a directory from a configuration file[[email protected] redis]#Mkdir-pv/data/mysql/mysql_3307/{data,logs,tmp}mkdir:created directory '/data/mysql/mysql_3307'mkdir:created directory '/data/mysql/mysql_3307/data'mkdir:created directory

One, backup the database separatelyMysqldump-uroot-poldboy Oldboy >/opt/oldboy.sql The simplest backup1) MySQL based MyISAM engineMysqldump-uroot-poldboy-b-x-f Oldboy | Gzip >/opt/oldboy.sql.gz2) After 5.5 The default is InnoDB

Clear screen:　　CLS can clear the screen as long as it enters the CLS and then returns to run the command.View version number:MYSQL-V Note: V must be capitalized, if not uppercase is wrong ...　　Login:Mysql-u User name-p password-p port number-H

@echo Off &setlocal enableextensions::----------Configuration Items----------:: Backup placement path, plus \ Set Backup_path=E:\Backup:: The name of the database to be backed up, with multiple spaces separating set DATABASES=Test:: MySQL user Name

Before encountering a problem, the following brief description:The table structure is as follows:CREATE TABLE ' Testa ' (' id ' int (one) not NULL auto_increment,' CID ' int (one) DEFAULT NULL comment ' Product ID ',' UID ' int (one) DEFAULT NULL

MySQL5.0 introduces a new binlog format, binlog format 4,,binlog format 4 is designed specifically for extensions. The Binlog event is made up of 4 parts1 General Purpose headContains basic information about the event, the most important of which is

New User:Create user username; --Create an empty password user.Create user username identified by ' password '; -Create a password when creating a new user.Grant Select[,insert ...] on Mysql.user to username identified by ' password '; --Create a

One or four types of logs1. Error log: Log the start, run, and shutdown process of MySQL server, ending with. Err by defaultMysql> Show variables like ' log_error ';2, binary log * * *Documenting all DDL and DML operations that a user makes to a

This article will focus on some of the common syntax differences between MySQL and SQL Server, as well as the related content of common stored procedures. 1. identifier qualifier SQL Server[]MYSQL "2. String addition SQL Server directly

Reference: Win 10 installing MySQL 5.7Website:http://blog.sina.com.cn/s/blog_5f39af320102wbk0.htmlThis article refers to the tutorial on the URL above, thanks to the author for sharing.I installed the decompression version, because the installation

Transferred from: https://my.oschina.net/iceman/blog/53735If an on DUPLICATE KEY UPDATE is specified at the end of the INSERT statement, and the row is inserted, it causes duplicate values to appear in a unique index or primary KEY.The update is

Solve the problem of Chinese garbled characters in Mysql5.7 and Chinese garbled characters in mysql5.7 When using mysql5.7, you will find garbled characters appear after you write Chinese characters to the database through the web end. However,

Mysql 5.7.17 installation tutorial attached MySQL service cannot be started solution, 5.7.17mysql For most. net development, Microsoft's SQL server database is quite familiar, and MySQL and Oracle have been used before, but they are all very

Solve the problem that Mysql5.7.17 fails to be installed and started in windows, mysql5.7.17windows First install MySQL on the machine, Windows 7 The mysql installation file is in zip format and the version is 5.7.17. After decompression, the

Why is MyISAM faster than Innodb?INNODB requires much more maintenance than the MYISAM engine during SELECT:1) Data blocks, INNODB needs to be cached, and MYISAM only caches index blocks, which also reduces the number of swap-in and swap-out; 2)

MySQL writes the statement into the binlog binary log, mysqlbinlog Because binary logs are public resources, binary logs must be written to all threads, so you must avoid two threads updating binary logs at the same time. Therefore, when writing a