MySQL

Grant permissions on object to userA grant general data user, the right to query, insert, UPDATE, delete all table data in the database.Grant SELECT on testdb.* toGrant insert on testdb.* toGrant Update on testdb.* toGrant Delete on testdb.*

Linux Start/stop/restart MySQL database method1. View MySQL versionMethod one: status;Method Two: Select version ();2. mysql start, stop, restart common commandsA, starting mode1. Start with service:[[Email protected]/]# Service mysqld Start (5.0

First, the basic concept1, MySQL "key" and "index" definition is the same, so the foreign key and the primary key is also one of the index. The difference is that MySQL automatically indexes the primary key for all tables, but the foreign key field

1. Connect to MySQL Databaseconnect_errno) {echo "Failed to Co Nnect to MySQL: ". $mysqli->connect_error;} else{echo "Success connected!";}2. Executing DDL statementsSQL statements can be executed by using the query method of the $mysqli object

unsigned is both non-negative, this type can increase the data length!For example if tinyint max is 127, that tinyint unsigned max can go to 127 * 2The unsigned property is only for integral types, whereas the binary property is used only for char

Check the status of the MySQL master- Slave synchronization architecture (from a master-to-one) from the database server  (IP Authorization, whether the server and Io are normal, from my SQL process is normal)Master mysql:192.168.1.10From mysql:1

First, crack MySQL database password step1. Modify the MySQL configuration file/etc/my.cnf[Mysqld]port = 3306socket =/tmp/mysql.sockskip-external-lockingkey_buffer_size = 256mmax_allowed_packet = 1Mt Able_open_cache = 256sort_buffer_size =

from:http://blog.163.com/[email protected]/blog/static/109463675201191173221759/MySQL add column, modify column, delete column's SQL statement notationALTER table: Add, modify, delete table columns, constraints, and other table definitions.

BackupIncremental backups are based on a full backup, so we need to do a full backup first:Innobackupex--password=test/backup/Note: Test is the password for the root user of my MySQL service,/backup/is the directory I used to store the backup

First, mathematical functionsABS (x) returns the absolute value of XBIN (x) returns the binary of X (Oct returns octal, HEX returns hex)CEILING (x) returns the smallest integer value greater than XEXP (x) return value E (base of natural logarithm) x

The optimization of MySQL is very important. The other most commonly used and most need to optimize is limit. MySQL's limit brings great convenience to paging, but when the amount of data is large, limit performance drops sharply. Same as 10

Architecture___ Master_mysql (10.10.10.3) |   |      Mysql-proxy (10.10.10.2) |           |___       | Slave_mysql (10.10.10.4)(i) MySQL master-slave synchronization1. Mysql-master setting(1)Server-id = 1//master End ID Number binlog-ignore-db

Ordinary string or expression is a placeholder 3 bytes, so utf8 enough, but the mobile side of the emoji placeholder is 4 bytes, the ordinary utf8 is not enough, in order to deal with the wireless internet opportunities and challenges, to avoid the

This article mainly introduces the configuration of Zabbix monitoring MySQL, including the use of Zabbix self-contained templates to monitor MySQL related information and custom key monitoring MySQL synchronization. at the same time, it introduces

Yi, CONCAT (str1,str2,...)Returns the string that results from the connection parameter. If any one of the arguments is NULL, the return value is null.Select Concat (s_id, "--", s_bar_code) from ' T_storage_order_detail ' WHERE ' s_sn ' like '%r20160

When designing a MySQL database, you always pay attention to the length and precision when designing floating-point types. Types such as int are automatically displayed as int (11) after they are added.This 11 is actually only a display width, does

Kider accessible by lift 1#  Posted in 2010-8-31 16:06:04 | Just look at the author | Reverse View | Reading mode  Source: mysqlpub.comthere are two functions in MySQL to calculate how many rows were affected

　　explain shows how MySQL uses indexes to process SELECT statements and join tables. can help select better indexes and write more optimized query statements .1. Create a databaseThe SQL statements are created as follows:/*Navicat MySQL Data

Mysql 5.7.9 installation-free configuration method graphic tutorial, mysql5.7.9 I will share with you the installation-free mysql 5.7.9 configuration method for your reference. The specific content is as follows: 1. decompress the MySQL

Linux mysql 5.6.17 installation text tutorial, mysql5.6.17 This article provides a simple version of the mysql 5.6.17 installation tutorial for your reference. The details are as follows: 1. Download mysql for linux (we recommend that you do not