if in mysql query example

One: Connection query:Connection query is to connect two or more tables according to a certain condition, select the required data, the connection query query two or more tables at the same time, when there are fields representing the same meaning

MySQL Query performance optimizationThe optimization of MySQL query performance involves many aspects, including library table structure, establishing reasonable index and reasonable query. The library table structure includes how to design

High Performance MySQL Reading Notes-query performance optimization, high performance mysql For high-performance database operations, it is not enough to design the optimal database table structure and build the best index. You also need to design

For high-performance database operation, it is not enough to design the optimal library table structure, and to establish the best index, but also need reasonable design query. If the query is poorly written, high performance cannot be achieved even

Installation RequirementsInstallation Environment: CentOS-6.3Installation Method: source code compilation installationSoftware Name: mysql-cluster-gpl-7.2.6-linux2.6-x86_64.tar.gzDownload Address: http://mysql.mirror.kangaroot.net/Downloads/Software

1. Full backup and incremental backup 1.1 full-scale backupFull-volume data is all the data in the database, and a full backup is the backup of all the data in the database.Back Up all libraries:mysqldump -uroot -p123456 -S /data/3306/mysql.sock -F -

Essays-66 Articles-0 comments-MySQL slow query (ii)-Pt-query-digest detailed slow query log one, Introduction Pt-query-digest is a tool for analyzing MySQL slow query, it can analyze Binlog, Gene RAL Log, Slowlog, can also be analyzed via

1. download MySql 1. download MySql Open http://www.mysql.com/downloads/mysql/#downloads download in browser My downloaded version is Red Hat 5 version of http://www.mysql.com/downloads/mirror.php? Id = 407552 Upload the file to the server, or

Turn on caching, set cache size, and implement the following: 1, modify the configuration file, Windows under the My.ini,linux is my.cnf; On the last append to the configuration file: The code is as follows Copy Code

This article is "high-performance MySQL" Reading notes Slow Query Basics: Optimizing data accessThe most basic reason for poor query performance is that there is too much data to access. For inefficient queries, we found that the following two