MySQL

Use length and char_length two functions Length: is a calculation of the lengths of a field a Chinese character is counted three characters, a number or letter is counted as a character Char_length: Whether Chinese characters or numbers or letters

Copy Code code as follows: DELIMITER $$ DROP PROCEDURE IF EXISTS getuserinfo $$ CREATE PROCEDURE GetUserInfo (in Date_day datetime)----Example--MySQL stored procedure name: GetUserInfo--Parameter: date_day date format:

One, uptime can view the running time of the system Show global status like ' uptime '; Second, use the Linux command to view Linux has a uptime to view the system's running time, but MySQL does not have this command But you can do it with the

Copy Code code as follows: --Build test tables and data CREATE TABLE WebUser (username varchar (10)); INSERT into WebUser values (' A1 '), (' A2 '), (' A3 '), (' B1 '), (' B2 '), (' B3 '); Commit --Establish a stored procedure drop

The use of functions: Group_concat (), the implementation of an ID corresponding to multiple names, the original is a multiline data, the name merged into one line. Its full syntax: Group_concat (expr) This function returns a string result with a

Tried google to several methods, did not solve, and then suddenly remembered in the launch of Apache, IIS port occupancy (because my Apache also uses 80 ports), so open the command line Netstat-aon|findstr "3306" Results show Silently in the

When you create a stored procedure Error message: Copy Code code as follows: ERROR 1418 (HY000): This function has none of the deterministic, NO SQL, or reads SQL DATA in its declaration and binary Loggi NG is enabled (for your

How do I create a memory table?Creating a memory table is very simple, just specify engine= MEMORY: Copy Code code as follows: CREATE TABLE ' tablename ' (' columnName ' varchar (256) not NUL) engine=memory DEFAULT charset=latin1

The basic difference:The MyISAM type does not support advanced processing, such as transaction processing, but InnoDB type support. MyISAM type tables emphasize performance, which is performed more than InnoDB types faster, but does not provide

basic Knowledge 1.mysql compilation installation 2.mysql 3rd party Storage Engine Installation configuration method 3.mysql main storage engine (myisam/innodb/memory) features 4. String encoding knowledge 5.MySQL user account Management 6.

My MySQL is the default UTF8 encoding, the database is also set up UTF8 encoding, the use of the program can add Chinese data, in CMD Use SQL statement new data are reported similar to incorrect string value: ' \xb2\xe2\xca\xd4 ' for Column ' title '

Create users and assign permissions; Copy Code code as follows: Insert into Mysql.user (Host,user,password) VALUES ("localhost", "Phplamp", Password ("1234"))//create User Grant all privileges in dbname.* to ' username ' @ '% ' identified

Basic form Property name RegExp ' Match method ' pattern characters for regular expressions ^ The part that matches the beginning of the character EG1: Querying records starting with L from the Info table name field SELECT * from info where

Generally speaking, C + + operation MySQL, to MySQL insert 10,000 simple data, very slow, incredibly 5 minutes,and open the business words, less than a second to be done! The specific implementation code is as follows: #include #include

The two days in the website moved, this site to move the use of direct packaging MySQL database and Web files in the form of migration, upload good MySQL data directory inside the database to the VPS MySQL storage database directory inside,

First, what is the MySQL table and partition What is a table, from the superficial point of view, is to divide a table into n multiple small tables What is partitioning, partitioning is to divide the data of a table into n multiple chunks that can

ERROR 1786 (HY000) "Environment description" msyql5.6.14 "Error Message" Executing the CREATE TABLE ... an error was encountered while select: Copy Code code as follows: DB1 [Test] [23:01:58]> Create Tablelgmnr_bak select * from

Create a MySQL user [root@xuhost opt]# useradd-g mysql mysql3307-s/bin/nologin-d/usr/local/mysql3307Create a data directory [Root@xuhost opt]# mkdir/mysqldata/dirdata/mysql3307 [root@xuhost opt]# chown Mysql.mysql-r-/mysqldata/dirdata/ mysql3307

Compile and install the first MySQL 5.1.33 cd/opt /usr/sbin/groupadd mysql /usr/sbin/useradd-g mysql mysql-s/bin/nologin-d/usr/local/mysql Tar- ZXVF mysql-5.1.33.tar.gz cd

MySQL database storage engine for MyISAM, in the case of large traffic, the data table is likely to be locked, which will cause users to connect to the site timeout and return 502, this time requires the MySQL database MyISAM storage engine to