MySQL

MySQL database table self-increment primary key ID is messed up and needs reordering.Principle: Delete the original self-increment ID and re-establish the new self-increment ID.1. Delete the original primary key:ALTER TABLE DROP ' id ';2. Add a new

I. OverviewMySQL's lock mechanism is relatively simple, and its most notable feature is that different storage engines support different locking mechanisms. For example, the MyISAM and memory storage engines use table-level locks (table-level

Describe statement:Grammar:describe table name;Simplified notation:desc Table NameAttention1. Two kinds of writing results are the same,2. You can not end with a semicolon,3. Multiple tables are not supported for simultaneous querying.Detailed

New database: Code:Create database name;Attention:1. Database name preferably using the _db suffix, easy to identify the user database,2. User-created database only user account and root are authorized to use.Example:Create database

Excerpt from: http://blog.csdn.net/caomiao2006/article/details/38568825today, Wang also gave us a lesson, in fact, MySQL processing high concurrency, prevent inventory oversold problem, at the time of last year, Wang has mentioned, but unfortunately,

BEGIN#遍历占领野地表还原军队 #UpdateArmforceSet Number=NumwhereTroopsid=(SelectId fromTroopswhereIsfrist=1 andCityid=Cityid)DECLARETIdDECIMAL( +,0)default -1; #occupyWild表的TroopsIdDECLARECidDECIMAL( +,0)default -1; #occupyWild表的CityIdDECLARETemp_tidDECIMAL( +

1. First download the Windows edition to http://dev.mysql.com/, Mysqlinstall, this software MySQL provides the software for installing the solution for the Windows platform. 2. Copy the My-default.ini under MySQL and create the My.ini in the same

In the previous article http://5148737.blog.51cto.com/5138737/1570274 how to make a MySQL hot backup in Linux, belonging to a master one from the situation, but most of the situation is more than one host backup to a slave, save equipment.Looking

To know the size of each database, proceed as follows:1. Access to the INFORMATION_SCHEMA database (information on other databases)Use INFORMATION_SCHEMA;2, query the size of all data:Select Concat (Round (sum (data_length/1024/1024), 2), ' MB ') as

　　This article is your own study notes, welcome reprint, but please specify the source:http://blog.csdn.net/jesson20121020　Recently, because of the need to learn the development of Android network to use the server, so under Linux configuration

First, the basic operation#mysql-H localhost-u root-p;//link MySQL#mysql-u root-p password 123456;//Modify the root user password to 123456>show databases;//View data exists>create database db1;//Creating the Databases DB1>use db1;//into the

first, the database paradigmin order to build a database with small redundancy and reasonable structure, we must follow certain rules when designing database. In a relational database, this rule is called a paradigm. A paradigm is a summary of a

Problem Recurrence (The following discussion is for Windows environments only):C:\appserv\mysql> Mysql-u Root-pEnter Password:ERROR 1045 (28000): Access denied for user ' root ' @ ' localhost ' (using Password:yes)Edit the MySQL profile My.ini(do

A stored procedure (Stored Procedure) is a set of SQL statements that are compiled and stored in a database inorder to accomplish a specific function. The user invokes execution by specifying the name of the stored procedure and the given

We know that MySQL read and write in the performance of the cost difference is larger, generally speaking the server top 20% write pressure, the other 80% of the pressure from reading, of course, it depends on the actual business situation.This

Sharing the sample database Sakila Installation Process in MySQL, mysqlsakila Generally, there is no data available for testing and use on a brand new MySQL server. MySQL provides us with some sample databases for basic operations and stress testing

Mysql modifies the database storage engine (InnoDB)The current example is to change the engine MyISAM to innodb.View the supported database engines and default database engines of the current databaseDatabase-supported engines and default database

Steps and solutions for importing MYSQL database structure in PowerDesigner We are using PowerDesigner today and want to import the MySql table structure to PowerDesginer, Follow these steps: 1, first of all to ensure that the machine installed

MySQL trigger LearningTrigger: a special type of thing that can monitor certain data operations and trigger related operations (insert, update, and delete). Some data changes in the table, it is expected that other data changes may occur at the same

Rotten mud: mysql5.5 database cmake source code compilation and installation, mysql5.5cmake This article was sponsored by Xiuyi linfeng and first launched in the dark world. I have also written an article on mysql5.0 source code compilation, which