MySQL

Linux uses Yum to install MySQL, as well as start, login, and remote access.1. InstallationSee if you have installed: Yum List installed mysql* -qa | grep mysql*To see if there are any installation packages: Yum List mysql*

We often copy the MySQL data directory directly into the new environment, and normally restart MySQL to use it, but sometimes we also encounter some problems:1, the program Access when prompted to find the table, the actual table already existsThis

The first stepLocate the tag in the \conf\server.xml folder and add a label , this tag is configured as follows:Name= "JDBC/WEBDB"//Database nameAuth= "Container"Type= "Javax.sql.DataSource" driverclassname= "Com.mysql.jdbc.Driver" url= "Jdbc:mysql:

MySQL replication is a great feature of MySQL, which copies data from one MySQL instance to another MySQL instance. The entire process is asynchronous, but due to its efficient performance design, the latency of replication is very small. MySQL

1. Changing the MySQL database character setModify/ETC/MY.CNF under LinuxModify My.ini under Windows[Mysqld]#default-character-set = UTF8Character_set_server=utf8 #这个是我添加的init_connect= ' SET NAMES UTF8

Recently in a hotel project, the outside network and do not let run data, can only run down the intranet. The data is then imported into the production environment. The amount of data is at the 100W level.A simple command exports the specified

1 on-line environment sometimes considering the need to do an incremental backup database, so write a simple script2 Add automatic tasks do it every hour or less.#!/bin/sh#author RuM#date 2015-07-10Bakdir=/tmp/mysqlbakBakdir_full= $BAKDIR/fullbakdir_

Display database:show databases;Use database (Connect database to switch database):use+ database name;Show a table in a database:show tables;Creating database: Createdatabase+ database name;To create a table:CREATE TABLE Student (ID int (4) primary

A. First stop the service/etc/init.d/mysqld stop and add it in/ETC/MY.CNF:Socket=/var/lib/mysql/mysql.sockSkip-grant-tablesUser=mysql Start MySQL service, enter MySQL login mysql> use MySQL;Reading table information for completion

1. Why should I use a trigger?Triggers are somewhat similar to functions and need to be declared and executed. However, the execution of the trigger is not called by the program, nor is it started manually, but is triggered by an event, which is

System Preparation before installation1.gcc-c++, ncurses Bag# yum Install gcc-c++ 2.GNU make package. It is recommended to install GNU make 3.75 or later, http://www.gnu.org/software/make/# yum Install make3. Install CMake, used to compile

1, Integer type Integer type Bytes Minimum value Maximum Value tinyint 1 signed: -128 unsigned: 0 signed: 127 unsigned: 255 smallint 2 signed: -327

In the My.cnf file, add:DataDir =/usr/local/mysql/datalong_query_time = # record the query time checked for 1 seconds. log-slow-queries =/usr/local/mysql/log/db-test2-slow.log# Log directory. #log-queries-not-using-indexes# represents a query that

OverviewChildren's shoes with MySQL know the need to build an index, but many people just stay in indexing to make the query faster However, in order to achieve this goal, it is very necessary to establish a scientific and rational index. Indexes

What is a long connection?In fact, a long connection is relative to the usual short connection, that is, long time to maintain the client and the server connection state.The usual short connection operation steps are:Connect-"data transfer-" close

MySQL binary log:Command-line arguments:--log-bin[=file_name] File name--log-bin-index[=file] file Index--max_binlog_size Single File size--binlog-do-db=db_name to those DB records. Record only for the specified database--binlog-ignore-db=db_name

Union: The union means to merge two or more query results together.Note: two queries must have the same number of columnsThe type of the column can be different, but it is recommended that each column of the query want the corresponding type to be

First of all, this is the path here. and statements are in the Internet to see a lot of errors after their own practice after the change, I hope to be useful to everyone.Here in the installation of the time to follow my order. Otherwise, the

Original Address reference: http://www.cnblogs.com/ringwang/archive/2008/07/05/1236292.html1. Control Flow function1.1 Ifnull (EXPR1,EXPR2)If EXPR1 is not Null,ifnull () returns EXPR1, it returns EXPR2.Mysql> SelectIfnull (1,0); - 1MySQL>

In the process of site relocation, it is important to transfer data. Your database may already contain a well-designed set of data tables, and important data is generated during site operations. At this point you have to do a good job of migrating