how to generate unique id in sql

Http://www.cnblogs.com/lsx1993/p/4663125.html "Database primary key scheme in distributed environment" [Http://www.2cto.com/database/201309/243195.html] Using a self-added primary key ID is certainly the best fit when using only a single database.

How PHP generates a unique numeric ID, note that it is numeric, do not string the Reply content: How PHP generates a unique numeric ID, note that it is numeric, do not string the Landlord, you are a big problem. Twitter,weibo and so on have

Background: During this time, I will create some website programs for a tourism website. The data table is roughly as follows: the general situation of the database table is the Access database. There are two data tables: TC_TourCompany and

Unique indexIf the primary key is not set to a clustered index when it is created, it must be a unique nonclustered index. In fact, the unique index, the name Incredibles, is that it requires the value on that column to be unique. A unique index

Background: During this time, I made some website programs for a tourism website. The data table is roughly as follows: Figure 1 the general situation of the database table is because it is an Access database, there are two previous data tables:

How does mysql insert a field to a table? this field will randomly generate a unique code. how does mysql insert a field to a table? this field will randomly generate a unique code ------ solution ------------------ if php is used you can use uniqid

How Flickr generates a unique ID, a GUID. Consistency Hash. are not, use the MySQL key automatically increment can. There is a nonstandard extension in MySQL, the syntax is replace into, although inert on DUPLICATE KEY update also has the same

Address: http://blog.csdn.net/zjcxc/archive/2005/07/06/415711.aspx Author: zhujian1. How to understand SQL Server instances In the project implementation process, many users need to develop a new SQL Server-based system. After the system is accepted,

Recently, someone asked me in the forum how to quickly generate an 8-bit number that is not repeated in 1 million. There are several points to note for this question: 1. How to generate an 8-bit random number. The more random the number is, the

GUID, the abbreviation of "Global Unique Identifier", is a unique reference number used as an Identifier in computer softw Is.GUIDs is usually stored as 128-bit values, and is commonly displayed as + hexadecimal digits with groups separated by H