MySQL

One of the prerequisite skills for database performance optimization when using indexes. In the MySQL database, there are four kinds of indexes: the focused index (primary key index), the normal index, the unique index, and the full-text index

Describe Specification Example Link Database Mysql-u User name-p password Mysql-uroot-proot Exit database Exit,quit,ctrl+d * Show Database version Select version (); *

Method 1: Use the Set password commandFirst log in to MySQL.Format:mysql> set password for user name @localhost = password (' new password ');Example:mysql> set password for [email protected] = password (' 123 ');Method 2: Use MysqladminFormat:

Long_retid =-1; Connection Con=NULL; Try{con=Queryrunner.getdatasource (). getconnection (); Queryrunner.update (Con, sql.tostring (), Val); Object _ret= Queryrunner.query (Con, "select last_insert_id () from" + Gettablename

Backup:mysqldump-uroot-p**-a-b-F--master-data=2--single-transaction--events >/root/all.sqlRecovery:mysql-uroot-pvaren2100* Incremental recovery with Binlog logsTake advantage of location recovery:Mysqlbinlog--start-position= "154"--stop-position= "78

Common operations for MySQL under Linux: Display Databaseshow databases; Select DatabaseUse database name; Displaying tables in a databaseShow tables; Show the structure of a data tabledescribe table name; Show records in a tableSELECT *

First, database management system1. RDBMS relational database features① Two-dimensional table② Typical products Oracle traditional enterprise, MySQL is the Internet Enterprise products③ data access via SQL④ the greatest features, data security is

Difference:1. InnoDB support transactions, MyISAM is not supported, for INNODB each SQL language is encapsulated as a transaction by default, auto-commit, which affects speed, so it is better to put multiple SQL language between Begin and commit,

1, use distinct to weight (suitable for querying the total number of the whole table)There are multiple schools + teachers to contribute, need to count the total number of authorsSelectcount (author)As total from files each author has a lot of

Environment[Email protected] ~]# cat/etc/redhat-7.1. 1503 ~]# uname-3.10. 0-229. el7.x86_64 #16each:2015 x86_64 x86_64 x86_64 gnu/linuxHost IP NAME Describe10.0. 0.10 node1 main load 10.0. 0.11 node2 standby

★ Programming OptimizationOne, character encoding (MySQL console garbled output resolved: character_set_results= ' GBK ')Table/Column encoding settingsColumns: ALTER TABLE name change column list name data type character Set character set nameTable:

Go locally and use the cmd command to connect to MySQLMysql-uroot-prootExecute the following command to open Data remote link permission (the first root refers to the user; the second root refers to the password)' Root '@'%'root' with GRANT

1. MySQL master-Slave synchronization configuration 1.1. Basic informationDatabase master server ip:127.0.0.1Database from server ip:192.168.1.311.2. Primary server configuration file My.ini configuration (Master)[Mysqld]#打开日志 (the host needs to

I. BACKGROUNDResc table preserves the system's first-level, two-level functional modules, while preserving the function of the two-level function module pages, the PID defines the parent-child relationship.Want to through the Resc table, sorting out

In the incremental deployment of the system, often need to provide incremental modification of the script, if it is to modify the stored procedures or custom functions, it is good to change, do not worry about the table function to be affected.What

One. Isolation level:The SQL standard defines 4 isolation levels, including specific rules that define which changes within and outside a transaction are visible and which are not.Low-level isolation levels generally support higher concurrency

Method 1: Use the Set password commandFirst log in to MySQL.Format:mysql> set password for user name @localhost = password (' new password ');Example:mysql> set password for [email protected] = password (' 123 ');Method 2: Use MysqladminFormat:

At the time of creationCREATE TABLE si (Id INT auto_increment)Automatic numbering, can not have more than one automatic column (can be automatically coded for you)If you add a column to it in a S11 form (this is not the same as inserting data)ALTER

1. Views ViewA view is a virtual table whose contents are defined by a query. A filter that defines a view can come from one or more tables or other views of the current or other database.Advantages of the View:① simplifies operations by defining

Transfer from https://www.cnblogs.com/wsl222000/p/5445768.html1. Installing the mysql-5.5 Yum sourceRPM-IVH http://repo.mysql.com/yum/mysql-5.5-community/el/6/x86_64/mysql-community-release-el6-5.noarch.rpmTo install MySQL5.6, you can