MySQL

One. Char and varcharChar is a fixed-length query that is faster than the varchar speed . The disadvantage of char is that it wastes storage space .When retrieving a char column, the returned result removes trailing spaces , so the program needs to

CentOS 6.4 MySQL Installation1. Remove the original MySQLRpm-qa | grep mysql//This command will check if the MySQL database is already installed on the operating systemIf there is, we can unload it by RPM-E command or rpm-e--nodeps

Database introduction, Common classification Getting started with MySQL MySQL installation configuration MySQL multi-instance installation configuration MySQL Common basic commands MySQL database backup and recovery MySQL Log

Java Connection MySQL needs a driver package, the latest version is:http://dev.mysql.com/downloads/connector/j/, extract the jar library file, and then import the library file in the corresponding project.Download steps:Link: Http://pan.baidu.com/s/1

Database P3306CREATE DATABASE [if not EXISTS] db_name [characterset GBK];Use database;//Jump databaseshow databases;Alert Database db_name Character Set utf8;//modifieddrop databases [if not EXISTS] dbname;//Most usefulShow Create Databses

Common types:int integral typefloat decimalDouble decimalvarchar (20) string parentheses inside is the length of the write string only the string has parenthesesBit Boolean type dataDateTime Date-Time typeText LongInfrequently used types:Money

Online a bunch of installation tutorials, so do not repeat the specific installation process, only to say things to note. Novice recommended PhpstudyIf you want to install a single, then the following is my two or three years in the win Winserver

During the boring period, MySQL can be used when you insert tens of thousands of data tests at once.First create a table T3CREATE table t3 (id int) ENGINE = MyISAM;\d//The end sign of MySQL is changed to//by default the end sign of MySQL is;This

In the MySQL in statement is the appearance and the inner table as a hash connection, and the EXISTS statement is the external loop loop, each loop loop and then query the internal table. It is not accurate to say that exists is more efficient than

The method for copying MySQL query results to a new table (update and insert) and mysql query results In MySQL, you can copy the query results to another table. there are usually two types of replication: update existing data and insert a new

Detailed description of MySQL database installation and password configuration, detailed description of mysql MySQL was developed by MySQL AB and subsequently acquired by Oracle. MySQL is a relational database management system. Community edition

Differences between MyISAM and InnoDB In the MySQL storage engine: myisaminnodb InnoDB and MyISAM are the two most common table types used by many people when using MySQL. The two table types have their own advantages and disadvantages, depending on

C # How to efficiently read and write data to MySQL with massive data volumes, Prerequisites As a result of work, it is often necessary to process massive data and perform data crawling. Tens of thousands of GB of data is frequently used in a single

Navicat for MySQL: a simple method for exporting table structure scripts. navicatmysql Use the MySQL visualization tool Navicat to export the MySQL table structure script. 1. Right-click Database> Data transmission in Navicat ). 2. Select the

Differences between declare and set variables in MySQL stored procedures, mysqldeclare The variables defined by declare and those defined by @ set are often seen in the stored procedure. In short, declare defines local variables and @ set defines

20 + MySQL best practices and mysql20 Best Practices Database operations are the main bottlenecks in today's Web applications. Not only does DBA (Database Administrator) have to worry about various performance issues, but programmers have to worry

In-depth analysis of MySQL 5.7 Chinese full-text search, MySQL Preface In fact, full-text retrieval has been supported for a long time in MySQL, but it has always supported only English. The reason is that he has always used space as the separator

In-depth parsing of temporary tablespace in MySQL 5.7 and in-depth parsing of mysql5.7 Temporary table A temporary table, as its name implies, is a temporary table that has been destroyed. Data can be stored in both a temporary file system and a

Use of mysql row-level locks and prevention of deadlocks, mysqlI. Preface Mysql InnoDB supports transactions and row-level locks. You can use row locks to process user withdrawal and other services. Sometimes deadlocks occur when mysql locks are

What are stored procedures and triggers, and stored procedure triggers? The simplest way is to define a series of operations in SQL server. You only need to call them to complete the corresponding operations.==========================================