MySQL

Registered oracle Login Name: 10402852@qq.com Password: The number * after dsideal ******* is a common password of Wang Zhuo, but it is in uppercase, because the ORACLE password mechanism is strict. WINDOWS:   True:

Copy codeThe Code is as follows:Select CONCAT ('drop table', table_name ,';')FROM information_schema.tablesWhere table_name LIKE 'dede _ % '; "Dede" is the prefix of the table to be deleted. After this SQL statement is executed, a series of SQL

For example, errors such as "Got a packet bigger than 'max _ allowed_packet 'bytes" or "MySQL server has gone away" occur during Database Import, generally, the data imported is larger than the maximum package size limited by the system. The default

The reason is that the primary key must be unique, that is, there may be duplicates in the database with the current restored database. a restriction that Foreign Keys shoshould be uniquely named throughout the database, an effective method is to

Copy codeThe Code is as follows: 'mark' set ('index', 'best', 'hot ') There were few users and few people who knew about it. After a long time, I finally got a set of knowledge points.Looking at the above structure, MYSQL is not stupid. Will it

Copy codeThe Code is as follows:Select *, (2*6378.137 * ASIN (SQRT (POW (SIN (PI () * (111.86141967773438-lat)/360), 2) + COS (PI () * 33.07078170776367/180) * COS (lat * PI ()/180) * POW (SIN (PI () * (33.07078170776367-lng)/360), 2 )))) as juli

View the current connection system parameters: show variables like '% char % ';Mysql> show variables like 'Char % ';+ -------------------------- + ----------------| Variable_name | Value+ -------------------------- + ----------------|

Recently, server problems have caused the company to lose a lot of website data. Smart softwares also lost a lot. I have been busy fixing data over the past few days. When we restore a customer's data today. A consistent problem was found. Multiple

During the execution of transactional statements, the server will perform additional processing. When the server executes multiple transactions in parallel, in order to record them together, the concept of transaction cache needs to be introduced.

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

Refer to the previous article to successfully log on to MySql in security mode, and then change the password, which is equivalent to setting a password for MySql. After logging in, you want to create a database for testing. The result is true:ERROR 1

When I interviewed mysqldba, I encountered a question: Describes the implementation principle of the msyql replication mechanism. How can I restore the database node of the slave with inconsistent data without stopping the mysql master

All JDBC applications have the following basic procedures:1. Load the database driver and establish a connection to the database.2. Execute SQL statements.3. processing result.4. disconnect from the database to release resources.Next we will take a

This error often occurs when you try to create a foreign key in mysql, which is very frustrating. You cannot create one. the error of the frm file seems to imply an error in the file permission of the operating system or other reasons, but in fact,

When I used the mysql database in my experiment today, I forgot my password and asked me to find it for a long time. Now I want to introduce my own method: I used mysql functions for testing.Copy codeThe Code is as follows:Mysql> select user,

Environment:PC: ubuntu 10.10 192.168.1.112 (master) 192.168.10.245 (slave)MySQL: 5.1.49-1ubuntu8. 1-logThe database test already exists in the master.First modify the mysql configuration file:/etc/mysql/my. cnf[Master]# Author: zhxiaCopy codeThe

MySQL is so open that you can easily adjust its default settings to achieve better performance and stability. Key variables to be optimized are as follows: 　Change the index buffer length (key_buffer) Generally, this variable controls the buffer

Reference Table: student Multi-field QueryCopy codeThe Code is as follows:Mysql> select id, name, birth from student;Query all fieldsCopy codeThe Code is as follows:Mysql> select * from student;Where specified QueryCopy codeThe Code is as

Copy codeThe Code is as follows:-- Create a databaseCreate table 'rate '('Uname' VARCHAR (300 ),'Object' VARCHAR (300 ),'Score 'varchar (300)); -- Insert dataInsert into test. rate (uname, object, score)VALUES ('aaa', 'China', '67 '),('Aaa', 'Math',

Create a triggerCreate a trigger with only one execution statementCopy codeThe Code is as follows:Create trigger name BEFORE | after trigger eventON Table name for each row execution statementThe trigger name parameter indicates the name of the