MySQL

MySQL mysqldump export only table structure does not export dataCopy CodeThe code is as follows:Mysqldump--opt-d database name-u root-p > Xxx.sqlBacking Up the databaseCopy CodeThe code is as follows:#mysqldump database name > Database backup

Background of Appearance:The company does a Redis-related project where MySQL stores a lot of statistics. such as client-reported data, redis instance data, application data, machine data and so on. Every day in the report, collection, due to the

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. You should try to avoid null values in the WHERE clause, otherwise it will cause

If you have been looking for a more efficient method than the MySQL like statement, let me introduce you to a few. Like statementSELECT ' column ' from ' table ' where ' condition ' like '%keyword% 'In fact, you can useLocate (position) and

In the reconstruction of the site, the data structure is usually modified, so add, delete, add the MySQL table field is unavoidable, and sometimes for convenience, but also increase the modification of the table or field comments, the same field

Chapter 9 PHP access to MySQL Database1. PHP process for accessing MySQL database Serverprior to learning MySQL, the " client / server " architecture was usedMysql>select * from A; --------"MySQL database server《 ---------When PHP accesses the

Unlike lamp, the Web service is Nginx, and PHP is a standalone service, and the service is called PHP-FPM. Nginx handles static requests directly, and dynamic requests are forwarded to PHP-FPM. Therefore, in the static page processing, Nginx more

#group by #group by + group_concat () #group by + aggregate function #group by + have #group by(1) Meaning of GROUP by: Group The results of the query in 1 or more fields, with the same field values as a group(2) Group by can be

Background Mysql/innodb's locking analysis has been a difficult topic. In the course of my work, my colleagues have often consulted on this issue. At the same time, the micro-blog also often receive the MySQL lock-related private messages, let

One, a pair of multi-table creation1. Create a primary tableCREATE TABLE Hosttable (CID varchar (+) primary key,CNAME varchar (100));2. Create a table fromCREATE TABLE Fromtable (PID varchar (+) primary key,PName varchar (40),Price Double,);3. To

For some systems with large data volume, the problem of database is not only inefficient, but also the data storage time is long. Especially like a reporting system, the time spent on data import every day can be as long as a few hours or more than 1

This morning, I intend to use Wampserver to build PHP environment on the local Win7 machine, to configure my own applet. Download the latest Wampserver 3.0.6 installation, found that MySQL has been unable to run, thought to be the Wampserver version

Today:SELECT * FROM table name WHERE to_days (Time field name) = To_days (now ());Yesterday:SELECT * FROM table name WHERE to_days (now ())-To_days (Time field name) 7 days ago:SELECT * FROM table name where Date_sub (Curdate (), INTERVAL 7 day) 30

1. Select the most applicable field propertiesMySQL is good at supporting large data volumes, but in general, the smaller the tables in the database, the faster queries are executed on it. Therefore, in order to achieve better performance when

Sqoop import MySQL data into HBase's blood and tears (for half a day) Copyright NOTICE: This article is Yunshuxueyuan original article.If you want to reprint please indicate the source: Https://my.oschina.net/yunshuxueyuan/blogQQ Technology

Analysis of mysql joint index and Where clause optimization, mysql clause Problem description:The sorting and conditions are removed one by one for testing. The result shows that the sorting is in the sorting part. The execution time is changed from

MySQL latency Association performance optimization method and mysql latency performance optimization Background] An error occurred while alerting the load of a business database. The cpu usr reached 30-40, which remained high. Use tools to view the

MySql index details and correct use methods, mysql index details MySql index details and correct usage 1. Preface: Indexes have a crucial impact on the query speed. Understanding indexes is also the starting point for optimizing database performance.

Briefly describe the differences between MySQL and Oracle, and briefly describe mysqloracle 1. Oracle is a large database, while Mysql is a small and medium-sized database. The market share of Oracle is 40%. Mysql is only about 20%. At the same time,

Batch add and delete mybatis -- (2) Delete mybatis 1. First, you should understand that the value of the number of affected rows in the int type is returned when mybatis is added, deleted, or modified.   Mapper Interface Package cn. xm. mapper;