MySQL

1. Use aLOCATE (SUBSTR,STR)POSITION (substr in str)The function returns the position of the substring substr the first occurrence in the string str. If the substring substr does not exist in Str, the return value is 0.mysql> SELECT LOCATE (' Bar ', '

Transactional in MySQL:MySQL's InnoDB engine is transactional, and transactions consist of multiple SQL statements, which are a contiguous set of database operations. The entire transaction succeeds only if every operation within the group succeeds.

MySQL four communication protocols (all the sockets on Linux that are locally connected are TCP)When MySQL is connected, when using-h127.0.0.1, the connection protocol under Linux and UNIX is the socket protocol, and Windows is the memory

1. mysql data type the type of data field defined in MySQL is important for optimizing your database. MySQL supports multiple types and can be broadly divided into three categories: numeric, date/time, and string (character) types.　　2. Numeric type

MySQL log: (The following are all bit global server variables)MySQL > show global variables like '%log% ';MySQL 6 Class Log Brief introductionQuery log: Default is off (generates a lot of writes)   All query-related statements Slow query log: Query

1. Turn off MySQL:#service mysqld Stop2. Transfer data:#cd/var/lib#ls#cp-A mysql/mnt/sdb/mysql/3, modify the configuration file, a bit three:#vi/etc/my.cnfAdd under [client]Socket=/mnt/sdb/mysql/mysql.sockComment out the previous code#datadir

Http://dev.mysql.com/doc/refman/5.7/en/innodb-memcached.htmlFirst, the test environmentmysql:5.7.15Centos:6.6_x86_64II. Installation and Deployment1. Installing Libevent# yum Install Libevent-y2. Execute Configuration SQL# Find/-name

There may be duplicate records in some MySQL data tables, and in some cases we allow duplicate data, but sometimes we also need to delete the duplicated data.In this blog post we will show you how to prevent data tables from repeating data and how

1. mysql Common commandsCreate database name; Create a databaseUse DatabaseName; Select DatabaseDrop database name deletes databases directly and does not alertShow tables; Show TableDescribe TableName; Detailed description of the tableAdd distinct

Toss for one hours, finally put the module connected to MySQL installed, Because my environment is PYTHON3.5,MYSQL official support to python3.4, the back Google to have pymysql die fast support python3.5, this module is written in Python, not much

The cause of the problem occurs:This problem occurs because the master-slave copy has been done before! Issue: Error 1201 (HY000): Could not initialize master info structure; more error MessaGes can found in the MySQL error logThe solution is to run

Rhel7/centos7/oracle linux7: 1 # RPM-UVH http://dev.mysql.com/get/mysql-community-release-el7-5.noarch.rpm Rhel6/centos6/oracle linux6: 1 # RPM-UVH http://dev.mysql.com/get/mysql-community-release-

Received a MySQL server load alarm, up a look, load average all soared to more than 280, with top A look, the CPU ran to 336%, but IO and memory load is not high, according to experience, should be an index caused by the tragedy.Look at the

What is a table partition A popular table partition is a large table that is split into several small tables based on conditions. mysql5.1 started supporting data table partitioning. such as: A user table has more than 10 million records, you can

Solve MySQL characters garbled ideas:MySQL server character setMySQL Client character setSystem Character SetProduction environment modified Character set:1. Export the table structure to the Scam.sql file2. Change the character set in the Scam.sql

Detailed tutorial on installing mysql 5.7 in centOS 7, centosmysql Reference official documents: https://dev.mysql.com/doc/mysql-yum-repo-quick-guide/en/ First create a repo File vim /etc/yum.repos.d/mysql-community.repo Then write data according to

Mysql 5.7: How to forget the root password or reset the password, mysqlroot After installing the MySQL database in Centos, I don't know the password. What can I do? Let's explain how to reset the password. 1. modify the configuration file my. cnf

Mysql batch update multiple records with the same field as different values, mysql multiple First, mysql updates a field of data, which is generally written as follows: UPDATE mytable SET myfield = 'value' WHERE other_field = 'other_value'; You can

MySQL FAQ and mysql questions1. Foreign key candidates for primary key superkeys Primary key: A combination of data columns or attributes that are unique and fully identified for the stored data objects in the database table.A data column can have

Implementation of grouping statistics for MYSQL every 10 minutes. Preface The content of this article mainly introduces the implementation method of MYSQL grouping statistics every 10 minutes. It will be very useful in drawing the user login and