MySQL

Linux CentOS, MySQL installation three ways: Binary tar package installation, RPM installation, yum installation (simplest)See if you have installed:Yum List installed mysql*Rpm-qa | grep mysql*To see if there are any installation packages:Yum List

Index Type:1. General IndexCreate index index_name on test_table (column_name (length));2, unique index, can have a null valueCreate Unique Index on test_table (column_name (length));3, primary key index, can not be empty4, combined index, follow

From the command prompt to the bin folder in the MySQL file directory, execute the commandMysql-u root-p DatabaseName Where root is your MySQL username, DatabaseName is the name of your database, and db.sql you are the file. Note You have to put

Development write a few statements, think the query results and logic a bit inconsistent, get here together to analyze the next.The statements are as follows:SelectTp.title, Tp.amount,ifnull (sum( Case whenTu.type= 1 ThenTi.invest_amountElse 0 End)

SQL Simple Command Description: Mysql.exe-u User name-p password-H IP address show databases; View the database The version number of the Select version ();p HP injection Use database (table name); Show tables; shows the table

1, Innodb_flush_log_at_trx_commit0: The log buffer is written once per second to the log file, and the log file is refreshed with disk operations, but no action is taken on a transactional commit.1: When each transaction commits, the log buffer is

MySQL database user creation, authorization managementCreate a User:Command:CREATE USER ' username ' @ ' host ' identified by ' password ';DescriptionUsername-the user name you will createHost-Specifies the host on which the user can log on, if

See which libraries > show databases are available;View the table > use DB for a library; Show tables;View table fields > Desc TB;View Build Statement > Show CREATE TABLE TB;Which user is currently > select User ();View current Library > select

One, Windows system installation MySQL　　MySQL is a relational database management system developed by the Swedish MySQL AB company, currently owned by Oracle Corporation. MySQL is an associated database management system that keeps data in separate

The official xtrabackup isHttp://www.percona.com/software/percona-xtrabackup.Xtrabackup contains two main tools, namely Xtrabackup and Innobackupex, which are distinguished by the following:1 Xtrabackup can only back up the tables of the InnoDB and

Using length and char_length two functionsLength: Are the lengths of the calculated fields a Chinese character is counted as three characters, a number or a letter is counted as a characterChar_length: No matter Chinese characters or numbers or

Linux environment, after installing MySQL, not directly start the service, you must first initialize the database. The main tasks of initialization include: Initialize the files required for the database such as log, tablespace, etc;

Clean up MySQL database data based on field conditionsBackgroundA database on the line has 1000 db of library, disk alarm, each library size is not very big but add up is very big.Manually cleaning up the data based on the time field is not

Because when I was doing. NET, I played PHP, so I used the Wamp server, and then I did the Java project, and I always used the above MySQL.But in the middle appeared several times garbled, the amount, today changed again wamp MySQL

1. Create MySQL users, user groups, and related directories/usr/sbin/groupadd MySQL/usr/sbin/useradd-g MySQL

MysqladminMysqladmin-u User-p password ' new password ' ==> change passwordMysqladmin-u User-P [-H remote server address] shutdown ==> can shut down the server locally or remotelyMysqladmin-u User-P status ==> view statusMysqladmin-u User-P

MySQL logical backup scheme: Logical backup for DB (in production environment due to small amount of data).mysql_backup.sh#!/bin/bashDate= ' Date +%f-%h-%m 'Mkdir/opt/backup/${date}-PUsesize= ' du-s/opt/mysql |cut-f 1 'biaozhun= ' df/opt/|awk '

table Partitioning refers to the decomposition of a table in a database into smaller, easier-to-manage parts according to certain rules. Logically, there is only one table, but the bottom layer is made up of multiple physical partitions.What are the

how does qt use MySQL to connect to remote databases? The code is as follows://Output available database Qdebug () MySQL driver failed to load, how to solve?  Workaround:Copy the Libmysql.dll from the MySQL installation directory to the bin

a MySQL overviewMySQL is a very popular open source database, when I turn from Oracle to do MySQL, the most profound thing is that this guy actually is the server and storage separate! And even more can not endure is, it unexpectedly is plug-in