MySQL

Database column typevarchar stringBit Bohr typeint integerfloat decimalChar characterDateTime date time does not fit need to turn downText binary/string (no length limit)Relationship1. Primary key2. Self-growth column3. Foreign keyFrom the tableMain

Recently on hand to do an auction of e-commerce projects.In the middle you need to set the auction state of the point to in progress.our solution is to Mysql Timer task, here is a simple summary. 1. Scope of Usenot all of them. MySQL version is

Installation module:#pip install ....MYSQLDB (2.x)Pymysql (3.x)Import MYSQLDB as SQLcon = Sql.connect (host = "localhost", #host host, local hostname or IP, refers to the hosts of the database you are connected touser = "Root", #user the username of

1. Locking this problem is automatically generated by MySQL, without the program ape themselves lockA: By default, when the document performs a insert/update operation, MySQL automatically locks the table. This allows the read operation to wait only.

1. Install pymysql;The 2.mac version is as follows:1 #-*-coding:utf-8-*-2 ImportPymysql3# The password I use * mosaic wow haha4conn = Pymysql.connect (host ='127.0.0.1', Unix_socket ='/tmp/mysql.sock', user ='Root', password ='******', db ='MySQL',

Brief introduction:Before this is through the mysqldump to back up the database, because it is a logical backup, so the use of this backup method of data is very safe, cross-platform, version is easy.There are pros and cons, logical backup in your

1. Data migrationDifferent apps connect different databases (examples of blogs with default database, BLOG4 with MySQL database)(1) to connect MySQL database, first download MySQL database and MySQLdb moduleDownload the MySQL Database reference

implementation structure: 650) this.width=650; "Src=" http://s3.51cto.com/wyfs02/M01/88/EC/wKiom1gAfT3B_dq_AAATIqhLvko501.png "title=" QQ picture 20161014143709.png "alt=" Wkiom1gaft3b_dq_aaatiqhlvko501.png "/>Prerequisites, this is the new

1. To optimize the query, avoid full-table scanning as far as possible, and first consider establishing an index on the columns involved in the Where and order by.2. Avoid null-valued fields in the WHERE clause, which will cause the engine to

There are more than 4W of data, but fuzzy queryVery slow to get up.1, tried to use SELECT * FROM (SELECT * From a UNION ALL SELECT * from B ... Many table union) as temptable where name like "%a%" and person_id like "%1%", found too slow.2, try to

1. Two MySQL on a native serverHttp://www.apelearn.com/study_v2/chapter25.html2. Two machines MySQL master/slaveMySQL server's master-slave configuration, which allows for read-write separation, or can be recovered from the standby library after the

First, Operation ideas:1) Stop the MySQL service2) Add "--skip-grant-tables" parameter at startup3) Change Password4) Restart MySQL serviceII. process of implementation# netstat -tunlp | grep 330*tcp        0       0 0.0.0.0:3306                 0.0.

User table: Users account, global permissions, non-privileged fieldsDB table: library-level permissionsHost: Obsolete, useless.Tables_priv: Table-level permissionsColumns_prive: Column-level permissionsProcs_priv: Stored procedure and storage

1) command-line mode# mysqladmin-u root-p ' redhat12345 ' password ' zabbix12345 '-s/data/3306/mysql.sock change password redhat12345 to zabbix123452) SQL statement modification methodmysql> update mysql.user set password= ' 12345 '  where user= '

1, three threadsMySQL replication is the asynchronous process from the primary server to one or more slave servers, where the entire replication process between the primary server and the slave server is implemented primarily by three threads, one

2.1MySQL Getting Started 1) Download to mysql website. 2) Install mysql software3) UseVerify successturn on cmd-- input mysql-u root-p Enter password returnC:\users\apple>mysql-u root-pEnter Password: * * *Welcome to the MySQL Monitor. Commands

1 Introduction Data is saved to memory:Advantages:1) Read and write very quicklyDisadvantages:1) data loss due to program shutdownData saved to file:Advantages:1) data can be saved permanentlyDisadvantages:1) Frequent IO operation, not high

1. A table association is an index that can take advantage of two tables, and if it is a subquery, at least a second query is no way to use the index.2. The first query executed to provide data to the main query is called a subquery3. If the

Create function through MySQLdb, createmysqldb Http://stackoverflow.com/questions/745538/create-function-through-mysqldb How can I define a multi-statement function or procedure in using the MySQLdb lib in python?Example:import MySQLdbdb =

MySQL 5.7 create VIEW or FUNCTION or PROCEDURE, mysqlprocedure 1. view. create algorithm = undefined definer = 'root' @ 'localhost' SQL SECURITY INVOKERVIEW 'sakila '. 'actor _ info' as select 'A '. 'actor _ id' AS 'actor _ id', 'A '. 'First _ name'