MySQL

SELECT * from Zan where UID does in (select UID from Zan where Zhongjiang!=0) group by UID ORDER by rand () limit 40But this is a relatively inefficient implementation and is finding a better way to use it.I think it's better to write separately

Mentioned earlier: Insert ... select ... where not existIn fact, it also seems to be implemented: when inserting data, do not insert if there are duplicates.See also: http://snowolf.iteye.com/blog/1568926and insert IGNORE into almost, but the former

Program: MYSQL 6.0 64 bitOperating system: WIN2008 64-bitThe first installation always fails, WIN7 or WIN2008 are the same.The first is about deleting MySQL:Stop the MySQL service in the service (start-up---control panel--services--service). Open

Recently found that the MDT launched the system has a different problem, the problem is not said, mainly the policy permissions are inherited by the domain. For example, we manually installed a lot of things are not configured strong state, push the

Today do inference insert used in MySQL on DUPLICATE KEY UPDATE, now Mark below!If you want to be able to insert data and update data without data in the database, you can choose on DUPLICATE KEY update.On DUPLICATE key update can run an update

Ubuntu14.04 out for a while, a few days ago just upgraded to this version, a fresh one. However, there is a small problem when installing MySQL, record for later use.Pre-operation:There are many ways to install MySQL online, there are roughly three

20140530-mysql insert Chinese question and take notes again1 , script statementsbefore importing, first CharSet GBK . To modify the table field encoding:Note: The console will make an error if the data is inserted in the import mode. Executed in our

today to learn to add to the table, write a blog summary, PS: All of the following comments are all my computer on the completion of the operation, and then copied to the Notepad added. As for the implementation of the time can be added to the

System centOS-6.3 method operation is very simple, as follows: #/etc/init.d/mysql stop # Mysqld_safe MySQL--skip-grant-tables--skip-networking & # mysql>use MySQL;mysql> UPDATE user SET Password=password (' NewPassword ') where user= ' root '

A transaction is a series of steps for a logical unit of work. Transactions are used to ensure the security of data operationscharacteristics of a transaction :atomicity ( Atomic Nature )Consistency ( stability , consistency )Isolation ( isolation

Learn some knowledge of the database, write a blog to facilitate the carding and consolidate knowledge. about what is the database to give an example to illustrate, said may not be accurate, as long as the understanding of a general meaning is

Today, migrating a database from SQL Server to Linux MySQL, the migration is successful, but the application is not running, viewing the log discovery, the prompt to find the table, I noticed that the table names are case, and the table names in

The interface used to make a date comparison, to return a period of time the data list.The Data table field is "End_time", the time format is 2014-05-30 13:12:10, want to check the deadline for registration data.Select field name from table where

1. Creating a database means dividing a space in the database system to store the corresponding data 1. Create database name 2. Display database: Show databases;2. Delete Database 1. Syntax: drop database name; 3. Database Storage engine (table type)

When PHPnow is used as a web-developed server, we should have forgotten the PHPnow MySQL database password. What should we do at this time? ? Crazy ?, Next we will share a solution when we forget the password of the mysql database that comes with

MySQL Cluster Core ConceptsNDBCLUSTER (also known as NDB) is an in-memory storage engine offering high-availability and data-persistence features.NDBCLUSTER (also called NDB) is a memory storage engine that provides high availability and data

How can I set the installed phpmyadmin to automatic login! First, find config in the root directory. sample. inc. copy a file name in php and change it to config. inc. php (if config. inc. php file, you can directly modify the file), open config.

MySQL memory allocation-Quick Setting Solution If you only use the MyISAM storage engine, set key_buffer_size to 20% of the available memory (plus innodb_buffer_pool_size = 0) If you only use the InnoDB Storage engine, set innodb_buffer_pool_size to

MySQL Workbench is a visual database design tool recently released by MySQL AB. This tool is a dedicated tool for designing MySQL databases. MySQL Workbench has many functions and features. This article, written by Djoni Darmawikarta, shows some of

1. duplicate values in the innodb auto-increment Column Start with the problem and reproduce the bug. use test;drop table t1;create table t1(id int auto_increment, a int, primary key (id)) engine=innodb;insert into t1 values (1,2);insert into t1