MySQL

1, Charchar maximum length is 255 characters, note is character number and character set It doesn't matter. 1) can have default values,2) The trailing space will be truncated.3) 255 characters can be saved regardless of Chinese characters, English,

Xunyu (nickname)Background: In view of the devastating damage to the QAS database, it was extremely sandy. In order to avoid this bath water situation again, we found a solution. Here to share how to implement a scheduled backup MySQL database

Private ObjectBlubckmysql (list List,stringConnect) { varSqllist = list. Select (item =string. Format (@"INSERT INTO Xiaoyao_blogs_picture (classifyname,pictureurl,pictureintroduce,username,addtime) VALUES (' {0} ', ' {1 } ', ' {2} ', ' {3

In the operation of MySQL, often need to convert characters into numbers, this step is simple, but not commonly used words are easy to forget, now will be found on the Internet The method is recorded as follows:1. Convert the number of characters to

This document records the modification of the Java, Tomcat deployment, and MySQL database for the Olds Web site after the completion of the CentOS installation, and the red part is the actual operation process.Initial conditions: CentOS installation

1.union is the merging of the results of two or more SQL statements into one result set. (Note: When merging, each statement must have the same number of columns, with the column name whichever is the first SQL statement's column name)Example:Select

Amoeba for MySQL is committed to MySQL's distributed database front-end agent layer, which mainly serves as the query routing function when the application layer accesses MySQL, focusing on the development of distributed database proxies. is located

Excerpted from onefish database1. Calculate the number of yearsYou want to count the age of the person by birthday. SELECT date_format (From_days (To_days (now)-to_days (@dateofbirth)), '%Y ') + 0; 2. Two time

Creating a database: Create databases mysql_db;Delete databases: drop database mysql_db;View database: Show DATABASES;Using the database: Use mysql_db;View tables in the database: show TABLES;To create a table:CREATE TABLE User (ID SMALLINT UNSIGNED

Ubuntu installed after MySQL, using the apt-get Install command, default to consent only local access[Email protected]:~/software# mysql-uroot-p123456-h10.16.115.101-p3306ERROR 2003 (HY000): Can ' t connect to MySQL server on ' 10.16.115.101 '

View:The view itself is a virtual table and does not hold any data.When accessing a view using an SQL statement, the data it returns is generated from other tables by MySQL.Views and tables in the same namespace, MySQL is treated similarly in many

1. Database Startup:Service mysqld start;******.pid failed Data folder does not have write permission chmod–r 755 Data/usr/local/mysql-proxy/bin/mysql-proxy--DEFAULTS-FILE=/USR/LOCAL/MYSQL-PROXY/CONF/ONLINE.CNF &or:

Based on the previous article method, the batch command is added to enable automatic backup. It is only because the name of the backup file in the batch command is special in terms of time, so it's a special sort of article.1. Copy the date folder

In order to better optimize MySQL in high concurrency, it is necessary to understand the locking table mechanism when MySQL query is updated.I. OverviewMySQL has three levels of Lock: page level, table level, row level.The MyISAM and memory storage

On the Internet to check some of the MySQL coding related information, here to tidy up, the wrong place to welcome you to criticize. 1. mysql character set-related variables:-Character_set_server: Default internal operation character

To view the log-related global variables:Mysql>show GLOBAL VARIABLES like '%log% 'To modify a related variable:1. For switching a function, use set GLOBAL xxx=xxx.2. Related to the operation of the file, can only modify the configuration file, add

The previous development has been using SQL Server database, prompting the plugin to use SQL Assistant, writing the kicker is quite efficient. This time the company transformation to use MySQL database, trial MySQL Workbench, MySQL Query browser and

When MySQL processes two integer (int) subtraction, if one of them is unsigned INT, the result is treated as unsigned.If the result of subtracting is a negative number: Before MySQL 5.5.5, the result becomes the largest integer (184467440737

MySQL database ' replication ' approach 2006-01-17 10:36:00 Tags: mysql SQL database casual workplace >mysqldump wap-u Root-ppassword--add-drop-table | MySQL test-u Root-ppasswordIn this way, the local WAP database is copied to the test database. Of

Encoding: Computers are binary storage, so the display symbols need to be converted to binary numbers to be stored, and each character is converted into a binary number, which is the character encoding.Character SetCharacters are used to display