MySQL

Today you need to update the MySQL version of the Linux server from 5.1 to 5.7, so the following is a record for future installation manuals Step one: Check the Linux operating system version Copy Code code as follows:

There may be duplicate records in some MySQL tables, and in some cases we allow duplicate data to exist, but sometimes we also need to delete these duplicate data.In this section we'll show you how to prevent duplicate data from appearing in a

MySQL stored procedure parameters (in)MySQL stored procedure "in" parameter: similar to the value of the C language function parameter, this parameter may be modified internally by the MySQL stored procedure, but the modification of the in type

It has always been thought that there are two bytes to record the length (a small length can also be recorded in a byte), so the problem was very boring at that time, but then some people in the group to explain, suddenly found that the original

The contents of an empty MYSQLL table are common in two ways: a delete and a truncate. Delete statements without a where parameter can delete all content in the MySQL table, and you can also empty the MySQL table with TRUNCATE table. Efficiency

The ON clause differs from the WHERE clauseA better understanding with WHERE ... Simple method of complex matching criteria for IS NULL clauseThe difference between matching-conditions and where-conditions A reminder of the "a left JOIN B on

Objective: To monitor whether the MySQL master-slave database is synchronized, if it is not synchronized, record the failure time, and execute the command to restore the synchronization status. 1. Create script file

Online check, there are two methods, the first one of the most Earth method: Use like sentence the second to listen to Brother Tao said using Full-text index, online search: How to get better full-text search results in MySQL Many Internet

No more nonsense to say, directly to everyone paste code. 1, Digital Auxiliary table Create a table CREATE TABLE test (ID int unsigned NOT NULL primary key); Delimiter//CREATE PROCEDURE pnum (CNT int unsigned) begin declare i int unsigned

Problem: MySQL DNS anti-solution: Skip-name-resolveThe error log has a similar warning: 1.120119 16:26:04 [Warning] IP address ' 192.168.1.10 ' could the not to resolved:name or service not known2.120119 16:26:04 [Warning] IP address ' 192.168.1.14

One, background Before using SQL Server for table partitioning, there were a lot of questions about unique indexes: Step8:sql Server When table partitions encounter a unique constraint, I did not think that in the MySQL partition will encounter the

Burst field length ORDER BY num/* Matching fields and 1=1 Union Select 1,2,3,4,5.......n/* Storm field position and 1=2 Union Select 1,2,3,4,5.....n/* Using built-in functions to storm database information Version () database () User () No

The MySQL RAND () function call can produce a random number between 0 and 1: Mysql> SELECT rand (), RAND (), Rand (); +------------------+-----------------+------------------+ | RAND () | RAND () | RAND () | +------------------+--------

Usually there is a field in the table that creates date, and other databases have the option of default values. MySQL also has a default value of timestamp, but in MySQL, not only is the insertion of the modification will also update the value of

Start from a problem Recently, the bank of this matter more serious ah, many depositors of the money in the bank, it disappeared, and the bank does not ask, said the user's responsibility, litigation, users can also lose, this is "socialism." Let's

A few years ago, Handlersocket turned out to let people in front of a bright, I also wrote an article introduced its usage sketch, today, for a variety of reasons, handlersocket not really popular, but fortunately the MySQL official inspired by it,

The InnoDB database is marked as deleted and does not really release the disk space it occupies, which results in a growing InnoDB database file. If you set up innodb_file_per_table=1 when you create the database, InnoDB creates a data file for

Crossday discuz! Board (referred to as discuz!) is Beijing Kang Sheng New Technology Co., Ltd. launched a set of common Community forum software system. Since June 2001, discuz! has more than 14 years of application history and more than 2 million

Data tables have been created, assuming that we have inserted a lot of data, we can use the way we like to retrieve and display the information in the datasheet, for example: You can display the entire datasheet as follows SELECT * from

deep analysis of backup and restore of MySQL database under Linux1. Backup[Root@localhost ~]# cd/var/lib/mysql (access to MySQL library directory, adjust directory according to your MySQL installation situation)[Root@localhost mysql]# mysqldump-u