MySQL

To create a user:CREATE USER ' username ' @ ' host ' identified by ' password ';User delete:DROP USER ' username ' @ ' host ';Create a user and authorize:GRANT privileges on Databasename.tablename to ' username ' @ ' host ' identified by ' password '

System Description: CentOS 6.4 mysql:5.5#查看磁盘并配置一块lvs磁盘方便后续db文件空间不够的问题Fdisk-l | grep "^disk/dev/*" vgspvcreate/dev/sddvgcreate mysqldb/dev/sddlvcreate-n mysqldba-l 99.9G Mysqldblvs#创建mysql安装目录Mkdir/mysqldata# Create MySQL UserGroupadd mysql-g

1. Need to go to the official download MySQL connect/.net driver, address: Http://cdn.mysql.com//Downloads/Connector-Net/mysql-connector-net-6.9.9.msi2. Create a simple project and refer to the file:3. Enable Data migration:

mysql-recursive Query method analysis, brother even education to help you do a simple collation: the need for friends can refer to ha.First of allTable structure and dataCREATE TABLE ' class ' (' ClassID ' int (one) not null auto_increment, ' Banji '

If an on duplicate key update is specified at the end of the INSERT statement, and the row is inserted to cause duplicate values in a unique index or primary key, update is performed on the row where the duplicate value occurs, and if the unique

Basic Configuration you need to look at the following 3 configuration items frequently. Otherwise, it may soon be a problem. 　　Innodb_buffer_pool_size: This is the first option you should set when you finish installing InnoDB. The buffer pool is

Install this oneself is to abuse oneself again;1. Installing python2.72. Installing django1.10These two installations are relatively simple, the online example is also a lot of clothing basically no error,When you're done testing, be aware that

To add a field: --Add Field--ALTER TABLE tb_name ADD field Name field type [integrity constraint] [first| After]--Add a card field to User10ALTER TABLEUser10ADDCardCHAR( -);--with integrity constraints.ALTER TABLEUser10ADDTest1VARCHAR( -) not NULL

1. Run the NPM install MySQL module for NODEJS in the project directory;2. Create db.js module to connect MySQL and define query method;varMySQL = require (' MySQL ');//Create a database connection poolvarPool =Mysql.createpool ({connectionlimit:50,

1. Insert a local file into the database, the database field is saved with textpublic static void Main (string[] args) {Propkit.use ("Pro.txt");Druidplugin Druid = new Druidplugin (Propkit.get ("Jdbcurl"), Propkit.get ("user"), Propkit.get

Create table test(a int, c int);Insert into test(a,c) values(1,3) on Duplicate key update c=c+1;If you insert multiple rows of records (assuming A is a primary key or a is a unique indexed column):Insert into test (a,c) values(1,3), (1,7) on

Configure hive to use the MySQL database------------------------1. Download and pressure hive.tar.gz2. Configure Environment variablesHive_home= ...Path=: $HIVE _home/bin: $HIVE _home/conf$>source/etc/environment3. Create a configuration file$>CD

Automatic cleanup Dynamic settingsExecutes the query in the terminal to check the current binary log timeout.The default is 0, which means never time outmysql> show variables like ‘%expire_logs_days%‘;+------------------+-------+|

1: First upload the generated. sql file xftp to the server root directory2: Enter Mysql===============mysql-u root-p3: Build the database ====================create database dyxw;4: Into the library ====================use Dyxw;5: Import ============

Focus:Left join is to find out the table 1 (the most left-most table in the statement), even if Table 2 (the most right table in the statement) does not match (with null display)The right connection is to find out the table 2 (the most right table

The best index is to improve the query speed of the data in the table, as important as the directory of the book, you can quickly find the required knowledge.Above is a table of more than 110,000 data, using a statement query, such as:Time:

CentOS 6.5 Minimized compilation install MySQL 5.5.35 configuration multi-instance1. Turn off the firewall[[email protected] ~]# service iptables stopiptables: setting chains  to policy accept: filter          [ 

Library operation: show databases;//Show All DatabasesDrop database dbName;//Deleting a databaseCreate DATABASE [ifNot EXISTS] dbName;//Create a databaseUse DbName;//Working with DatabasesShow tables;//displays the name of the table that is

(1) Index type: Btree Index: Abstract can be understood as "orderly" quick find structureBtree index is used by default in Myisam,innodb Hash Index: Hash index calculation is very fast, but the data is randomly placed, unable to

Configuration of user and user permissions in the MySQL database, mysql user permissions Problem: when you use a remote tool written in a thigh to manage the Mysql database, all data is displayed normally, but you cannot delete or modify the