MySQL

SHOW STATUSLog on to MySQL directly under the command line to run the show status command. The query statement is as follows: The same statement also has show variables; and show status is used to view the MySQL running STATUS, which is similar to

1.Convert the number of a character to a number. For example, convert '0' to 0, which can be directly implemented by addition.For example, sort d in the pony table and define d as varchar.Select * from pony order by (d + 0)2. when performing ifnull

Mysql_fetch_array-- Get a row from the result set as an associated array or number array, or both Description: array mysql_fetch_array (resource result [, int result_type]) Returns the array generated based on the rows obtained from the result set.

Copy codeThe Code is as follows:#/Bin/sh# Check whether mysql server provides services normallyMysqladmin-u sky-ppwd-h localhost ping# Obtain the Current Status values of mysqlMysqladmin-u sky-ppwd-h localhost status# Obtain the current connection

1. Each client connection is divided into a thread belonging to the server process. The corresponding queries of the connection are all processed by this thread. 2. The Server caches the thread. Therefore, no threads are created or destroyed for

MySQL master/Master synchronization Configuration Server Name IP System MySQL Odd.example.com 192.168.1.116 Rhel-5.8 5.5.16 Even.example.com 192.168.1.115 Rhel-5.8 5.5.16 Assume that the

Mysql:Select count (*) from main_index; However, a syntax error is reported here. Method 1:Check the document as follows:Aggregate functions (AVG (), MIN (), MAX (), SUM () in column list clause are supported. arguments to aggregate functions can be

1. if many rows are inserted from the same client at the same time, use the INSERT statement containing multiple values to INSERT several rows at the same time. This is faster than using a single-row INSERT Statement (several times faster in some

MySQLTuner: http://github.com/rackerhacker/MySQLTuner-perl MySQLTuner usage:Downloading and using MySQLTuner is actually a very simple process: Wget mysqltuner. plPerl mysqltuner. pl If you 'd rather not invoke perl every time, just make it

This is the case: there are two tables, team table and people table. Each people belongs to a team and there is a field team_id in people. The following table creation statement is provided: Copy codeThe Code is as follows:Create table t_team(Id int

Cause:Group Buying development report indicates an error occurred during the update.Update the SQL statement as follows::Copy codeThe Code is as follows:UPDATE table_name d SET d. column_name = 'hangzhou'WHERE d. ID = 100976; The error message is as

The development environment of a company is usually deployed on the Intranet, and then there will be public servers for developers and tests. Therefore, there is often a need to connect to the server through ssh or a local mysql client, in my

MySQL 5.6 will automatically hide the password information in the log. This is not just obfuscation, and then stores the unidirectional hash value in the log file. You can disable Password Hiding for log files by setting log-raw = OFF. The log-raw

After the MySQL database receives a network connection, it first obtains the IP address of the other party, and then performs reverse DNS resolution on the IP address to obtain the host name corresponding to the IP address. Use the host name in the

The default encoding of the mysql database is not UTF-8. After installing mysql, start the service and log on to the mysql database. Run the show variables command to view the default encoding of the mysql database: The character set of the

I. concept:① Database Synchronization (master-slave synchronization-write data to the slave server while writing data to the master database)② Database Synchronization (master-master synchronization-two database servers write data to each other) Ii.

1. How to solve the problem of slow import of large batches of disordered data into InnoDB?Because of the primary key clustered index relationship, InnoDB is slower and slower to import without a primary key or non-sequence primary key. How can we

1. view the current character set: Copy codeThe Code is as follows:Show character set; 2. Delete mysql related directories Copy codeThe Code is as follows:Rm-rf/usr/local/mysql/* installation directoryRm-rf/var/lib/mysql database directory 3.

1. InstallationCopy codeThe Code is as follows:./Configure -- prefix =/usr/local/apache2 -- enable-so -- enable-rewrite -- enable-ssl Apache now has a pseudo-static function called built-in pseudo-static. 2. If there is no -- enable-rewrite

Mysql is often used in the development process to export and import Chinese tables. This article will detail how to use it. If you need it, refer1. Export data for utf8 first:(1) Export all tables of the source database:Copy codeThe Code is as