MySQL

Found_rows ()It is often possible to return rows with limit restrictions in SELECT statements. Sometimes you may want to know how many rows will be returned without a limit, but you do not want to execute the same statement again. Then, include the

The benefits of using MySQL master-slave replication are:1, the use of master-slave server This architecture, stability can be improved. If the primary server fails, we can use the slave server to provide the service.2, processing the user's request

binlog_do_db;binlog_ignore_db;This two parameter is used to control which database changes to log; The following is an example of binlog_ignore_db.if Binlog_ignore_db=studio;Use studio; INSERT into t (x, Y) VALUES (2,2);--This is not a binary log,

1.apt-get install git php5 mysql-server apache2 phpmyadmin2.sudo ln-s/usr/share/phpmyadmin/var/www3.Apache2 Configuration1. Restart the server:/etc/init.d/apache2 restart2. Shut down the APACHE2 server:/etc/init.d/apache2 stop3. Turn on Apache2

Method One: Use the SQL Statement command updateThe cryptographic function PASSWORD(string) that comes with MySQL is required to encrypt a plaintext password, but it cannot be decrypted. Set the password specifically for the Mysql.user (User Rights

Learning content:1. Rights Management:The simple understanding of MySQL permissions is that MySQL allows you to do things within your rights and not to cross the border. For example, if you are only allowed to perform a select operation, you cannot

http://blog.csdn.net/wobin/article/details/10266165After installing MySQL using the Yum command on CentOS, the default port 3306 can be used to start successfully, but in the/etc/my.cnf, the MySQL boot is unsuccessful and the following information

There are many ways to install the CentOS installation in this article and we introduce a very easy installation method, provided the network connection is normal. Step one: Enter the command wget http://dev.mysql.com/get/mysql-community-release-el7

Linux uninstall MySQLUninstall MySQL1. Find out if MySQL was previously installedCommand: Rpm-qa|grep-i MySQLYou can see two of the MySQL packages:mysql-4.1.12-3.rhel4.1mysqlclient10-3.23.58-4.rhel4.12. Delete MySQLDelete command: RPM-E--nodeps

Install MySQL online in CentOS and mysql online in centos There are many ways to install MySQL in CentOS. This article introduces a very easy installation method, provided that the network connection is normal. Step 1: Enter the commandWget http://

Uninstall mysql in linux and mysql in linuxUninstall mysql in linuxUninstall mysql1. Check whether mysql is installed before.Command: rpm-qa | grep-I mysqlWe can see two mysql packages:Mysql-4.1.12-3.RHEL4.1Mysqlclient10-3.23.58-4.RHEL4.12. Delete

Use Oracle to recover MySQL Data problems Today, I want to solve a problem. In my daily work, it is still very difficult to restore some nonstandard operations, such as drop, truncate, and delete, the drop operation is basically safe if recycle bin

MySQL study note _ 7_MySQL common built-in functions MySQL common built-in functions   Note: 1) it can be used in SELECT/UPDATE/DELETE and where, orderby, and having. 2) use the field name as a parameter in the function. The value of the variable

MySQL study note _ 9_MySQL Advanced Operations (I) MySQL Advanced Operations (I)   I. MySQL table replication Create table t2 like t1; # copy the table structure. t2 can learn all the table structures of t1. Insert into t2 select * from t1; # copy

MySQL RAND () optimization case analysis, mysqlrand As we all know, in MySQL, if order by rand () is used directly, the efficiency is very poor because it will be executed multiple times. In fact, this is also true if the equivalent query uses RAND (

Modify the data page size of Innodb to optimize MySQL. We know that the data page of Innodb is 16 KB, which is a rigid rule. There is no change in the system. We hope MySQL will support multiple data pages in the same way as Oracle in the

Some optimizations that MySQL can make when the association is complex. Yesterday, an optimization of complex associated SQL statements was processed. The optimization of such SQL statements usually takes into account the following four points: 1.

Use an instance to understand the usage of the MySQL prefix index. A warning was reported when I added an index in the test environment today. root@test 07:57:52>alter table article drop index ind_article_url;Query OK, 144384 rows affected (16.29

How to improve the storage efficiency of BLOB columns in InnoDB tables in MySQL, innodbblob First, we will introduce several key points about the InnoDB Engine storage format:1. InnoDB supports the use of shared or independent tablespaces. We

Four Methods for killing MySQL connections in batches and four methods for mysql Method 1Use the connection information in the information_schema.processlist table to generate a temporary MySQL connection statement file to be processed, and then