MySQL

Copy Code code as follows: List ($usec, $sec) = Explode (', microtime ()); $timer = (float) $usec + (float) $sec; mysql_query ($query, $active _db); List ($usec, $sec) = Explode (', microtime ()); $stop = (float) $usec + (float) $sec;

In the database optimization work, makes the data as small as possible, causes the table to occupy on the hard disk space as small as possible, this is the most commonly used, is one of most effective means. Because the reduction of data, relatively

First Kind Copy Code code as follows: #This File was made using the Winmysqladmin 1.4 Tool #2004-2-23 16:28:14 #Uncomment or ADD only the keys, you know. #Read the MySQL Manual for instructions [Mysqld] Basedir=d:/mysql

Copy Code code as follows: REPAIR table ' table_name ' repair form OPTIMIZE table ' table_name ' optimization tables The REPAIR table is used to repair damaged tables. The OPTIMIZE table is used to reclaim unused database space, and when

This problem occurs when the delete is followed by the condition. Delete from table_name WHERE condition When you delete data, the amount of space that the datasheet occupies does not change. When you do not follow the conditions directly delete.

This example describes a workaround for the Union clause in MySQL that does not support order by. Share to everyone for your reference, specific as follows: I know very little about db, this problem is only encountered in MySQL, I do not know other

When we do a table-by-MySQL operation, we will not be able to rely on MySQL's autoincrement to produce a unique ID because the data has been dispersed across multiple tables.Should try to avoid using the self-added IP as the primary key, for the

Verify that the MySQL service is available in the list of computer services (1) Right-click on the Desktop computer icon appears menu list options, selected management (there are several ways to open the computer Local Service list, here is just

drop procedure if exists pro_rep_shadow_rs; Delimiter | ---------------------------------- --Rep_shadow_rs --Used to process information additions, updates, and deletions --Update only data that hasn't been done since last time --According to the

Understand that MySQL must firmly remember its architecture diagram, MySQL is made up of SQL interface, parser, optimizer, cache, storage engine 1 connectors refers to the interaction with SQL in different languages 2 Management serveices &

In order to prevent security risks, we generally set up a separate database access account for each database, the account only has access to the database permissions. Let's take a concrete look at the following: 1, first we have to login phpmyadmin,

The MySQL database is one of the most common and commonly used databases of DBAs, and the extensive application of MySQL has also allowed more people to join in learning it. Here are some of the most common and commonly used experiences and

Learn PHP, using the WAMP installation package to build a php+apache+mysql environment, WAMP official download Address:http://www.wampserver.com/en/ . But the Wamp default username is ' root ', The password is empty. Now I need to change the

method One : Enter the MySQL installation directory to open the MySQL profile My.ini or my.cnf find max_connections=100 Modify for max_connections=1000 service to restart MySQLRecommend the first method, the modification is more convenient. method

Windows1, MySQL is some environment variables can be set, Can enter: show variables; you can view the current environment variable settings; 2, some of these variables are related to the setting of the character, Can enter: Show variables

The MySQL installation starts with two methods as follows: Method One (simple version): 1.cmd access to MySQL installed Bin directory: Mysqld.exe–install 2.net Start MySQL service startup (or select Computer-> (right) to manage-> service and

Click on the "SQL" tab at the top to enter the SQL command input interface. Enter the following command: Copy Code code as follows: Update Mysql.user set Password=password (' jb51$123456 ') where user= ' root '; Then click on the lower

There may be duplicate records in some MySQL tables, and in some cases we allow duplicate data to exist, but sometimes we also need to delete these duplicate data. In this section we'll show you how to prevent duplicate data from appearing in a

To learn MySQLunder Linux, the first hurdle is how to install and configure MySQL under Linux. We have the patience to do this once and for all. 　　System version: ubuntu14.04 MySQL version: mysql-server-5.5 mysql-client-5.5 　　First check if

And since InnoDB is a robust transactional storage engine that has a history of more than more than 10 years, some heavyweight internet companies (Yahoo,google NetEase, Taobao) often use My daily work also often contacts InnoDB, now InnoDB part of