MySQL

When using MySQL, you sometimes need to query records with unique fields. Although MySQL provides the keyword distinct to filter out redundant duplicate records, only one record is retained, but it is often used to return the number of records that

1. Download the free installation package from the official MySQL websiteProgram.2. decompress the package and copy the directory to the actual running directory. For example, D: \ Program Files \ mysql \ mysql3307. 3. Copy the my-large.ini to the

In the first section of this chapter, we also mentioned using query profiler to locate the performance bottleneck of a query. Here we will detail the usage and usage of profiling. To optimize a query, we need to know exactly where the performance

Preface Mysqlreplicaion is a simple architecture, that is, a MySQL Server (slave) replicates logs from another MySQL Server (master), then parses the logs and applies them to itself. In a replication environment, only two hosts running mysqlserver

MySQL query statistics for a single SELECT statement is often complex in writing statements. The following describes how to use only one SELECT statement to help you.   Where can I use a single SELECT statement to implement MySQL query statistics?

How to download and install the MySQL database: : Http://dev.mysql.com/downloads/. download the package and install it in double steps. ========================================================== ===== How to configure the MySQL database:

After a day, I finally got it done. MySQL has two modes: MyISAM and InnoDB. If MyISAM is used, the. frm. MYD. myi files will be stored in the data directory, so you can directly move the data to restore it After configuring the permissions. If it

The MySQL status of the server is as follows: Server version: 5.0.18-standard-LogProtocol Version: 10Server characterset: Latin1DB characterset: Latin1Client characterset: Latin1Conn. characterset: Latin1 This encoding may cause problems during

// If no data exists, insert new data $ SQL = "insert into {$ ECs-> table ('cat _ Lang ')} (cat_id, lang_id, cat_name, keywords, cat_desc) values ({$ cat_id}, {$ k}, '{$ Val ['cat _ name']}', '{$ Val ['keyword']}', '{$ Val ['cat _ desc']}') on

Table Creation   Create Table 'lil '('Id' int (10) Not null auto_increment,'Name' char (20) default null,'Birthday' datetime default null,Primary Key ('id') engine = InnoDB default charset = utf8   Data insertion: Insert into Lee (name,

Add new user account in MySQL You can create one in two ways.MySQLAccount: 1. UseGrantStatement 2. Direct operationMySQLAuthorization Table The best way is to useGrantStatement, because it is more accurate and has fewer errors.   Create a

From MySQL Manual   6. MySQL Synchronization The synchronization function was introduced in MySQL 3.23.15. It can copy data from one MySQL server to another. This chapter describes various replication features of MySQL. This section describes the

1. Optimize Your MySQL query CacheYou can enable the High-Speed query cache for queries on the MySQL server. It is one of the most effective ways to improve performance by quietly processing the database engine in the background. When the same query

I. Differences in Common commands of different versions Show innodb status \ G mysql-5.1 Show engines innodb status \ G mysql-5.5 User @ '%' about grant authorization mysql-5.5 does not contain localhost Ii. Main differences between MySQL 4.1/5.0/5

MySQL Official Website: http://www.mysql.com/downloads/ There are several versions available on this download page. 1. MySQL Community Server Community version, open source free, but does not provide official technical support.2. MySQL Enterprise

Today, I will continue reading the book "mysql database development" recommended by the instructor. I encountered a problem when I saw the foreign key association problem with the innodb database, in the book, you can modify the parent table and

I believe most people have encountered too many instances to install mysql. I believe most people only need to find a multi-instance installation tutorial and it will be easy to solve, but the more smooth the installation process, the more

When using mysql (show tables), you sometimes need to view the table and field information (whether the table and a field exist .)~~ PHP provides such related functions, such as mysql_list_dbs () and mysql_list_fields (), but the mysql_list_fields ()

The front-end time is related to a DB project. alanc reports a query. Using indexes is much slower than not using indexes. So I followed up and used explain to look at two different query results. The results of queries without indexes are as

I don't know if anyone has encountered such a disgusting problem: two tables are connected to the query and limit. SQL is very efficient. However, after order by is added, the statement execution time has become very long, extremely low efficiency.