MySQL

#1. Add a fieldALTER TABLEStudentADDStuageINT not NULL;#2. modifying fieldsALTER TABLEStudent Change Stuage SAgeVARCHAR( -) not NULL;#3. modifying table namesALTER TABLEstudents RENAME student;#4. Delete a fieldALTER TABLEStudentDROPsage;#1. Add a

2018.6.1MySQL database forgot root password resolved: Enter configuration file/etc/my.cnf Add a statement under [mysqld]: Skip-grant-tables Restart Mysqld:service mysqld Restart Login MySQL database without password: mysql-uroot-p

Original: http://bbs.landingbj.com/t-0-240751-1.html1. Using MySQL explain to detect SQL execution efficiency, explain shows how MySQL uses indexes to process SELECT statements and join tables. Can help select better indexes and write more optimized

Original: http://bbs.landingbj.com/t-0-243203-1.htmlIn some cases, MySQL can use an index to satisfy the ORDER BY clause without requiring additional sorting. The Where condition and order by use the same index, and the order by IS in the same

1.1. Shell script automatically compiles and installs MySQL1, enter the script fixed directory, write the automatic installation MySQL scriptcd/server/scripts/Vim zidong_bianyi-install_mysql.sh#!/bin/bash. /etc/init.d/functionsMysql_tool_dir=

the definition of master-slave synchronization:is a structured pattern for storing data.Primary: The database server accessed by the client is the primary library server masterfrom: connect the main library server, automatically synchronize all the

to see if the event Scheduler is currently turned onSHOW VARIABLES like ' Event_scheduler ';Turn on Event ViewerSET GLOBAL event_scheduler = 1;Create EventSyntax:CREATE EVENT [IF not EXISTS] Event_NameOn SCHEDULE SCHEDULE[on completion [NOT]

Basic management statements for librariesSHOW DATABASES; # Show All LibrariesCreate database name;Show create database name; # Display library creation informationdrop database name; # Delete LibraryUse library name; Enter databaseBasic management

Please check the supported Platforms page for the MySQL database version supported by the confluence system. You need to upgrade your MySQL database before installing confluence. If you migrated from another database to a MySQL database,

If the confluence prompt does not have a class file, you may have placed your JDBC driver in the wrong folder. If you receive the following error message, make sure that the confluenceuser user already has all the required database permissions

increase, delete, change, checkLibraryDATABASE1, CREATE DATABASE "add"Create Database dbname charset UTF8; #创建 database library name setting encoding UTF82, Query the library "check"Create Database dbname; #查询数据库的 Create information show

Confluence's Installation Wizard will guide you step-by-stage in configuring the MySQL database in confluence.Using a JDBC connection (default)JDBC is the recommended way to connect your confluence to the database.The Confluence Installation Wizard

Set up MySQL to allow external IP connectionsAfter the MySQL installation is successful, the MySQL database can be accessed locally by default. If other computers need access to the MySQL database, they need to be granted access.Operation Steps:

Install Red Hat 7.2 Development Pack Java package all installedDownload MySQL 5.7.12wget Http://cdn.mysql.com//Downloads/MySQL-5.7/mysql-5.7.12-1.el7.x86_64.rpm-bundle.tarSee if MySQL is installedRpm-qa | grep MySQLUninstall MySQLRpm-e–nodepsUnzip

Binlog logs are used to record all update data, and when our database fails, we can use the Binlog log to retrieve it.If there is a problem with the MySQL database, you need to recreate the Binlog binary file.# 查看日志，查出需要恢复的时间点mysqlbinlog

1. What is an index?Index is the data structure that helps MySQL to get data efficiently. You can get the essence of an index: An index is a data structure.Can be understood as "sequential quick find data structure"In addition to data, the database

Overall update upload speed is slow.1: Simple insert speed is slightly slower than mysqldataadapterWith DapperConfiguration file"1.0"encoding="Utf-8"?> "v4.0"sku=". netframework,version=v4.5.2"/> "sqlConnectionString"connectionstring="server=127.0

In the configuration file, you can specify the SQL file that was initially executed after MySQL startup, with the following syntax:Under [mysqld] Specify:Init-file= "D:/mysql/test.sql", followed by a specific SQL file value.Note that the following

Random query, the method can have many kinds. For example, all records are queried, and N records are randomly taken from the list. The use of the program can be implemented. However, the program implementation must query all qualifying records (at

Today, the supervisor lets me add two fields to each table in the database, there are hundreds of tables in the database, it is obviously too time-consuming to add one by one, and there may be errors, such as missing a few tables without