Alter Master Key

The logical design of database is a very broad problem. In this paper, the main key design of the table is discussed in the design of MS SQL Server, and the corresponding solutions are given. Primary key design status and problems about database table primary key design, in general, based on business requirements, based on business logic, the formation of primary key. For example, when sales to record sales, generally need two tables, one is the summary description of the sales list, records such as sales number, the total amount of a class of cases, and the other table record of each commodity ...

The complete collection of SQL statement operations deserves to be permanently stored the following statements are part of the MSSQL statement and are not available in Access. SQL classification: ddl-data Definition language (create,alter,drop,declare) dml-Data Manipulation Language (Select,delete,update,insert) dcl-Data Control Language (Grant,revoke, Commit,rollback first, briefly introduce the basic statement: 1, Description: Create number ...

Database security Policy Database security issues have been around the database administrator's nightmare, the loss of database data and the database by illegal user intrusion makes the database administrator physically and mentally exhausted. This paper puts forward some security policies around the security of the database, hoping to help the database administrator, no longer nightmares every night. Database security issues should include two parts: first, the security of database data it should be able to ensure that when the database system downtime, when the database data storage media is corrupted and when the database user misoperation, database data ...

Editorial Staff Note: This article is written by Sung Hsueh, senior project manager, SQL Server team. One of the most recent uses of SQL Server is to create managed SQL using the Windows Azure infrastructure services of http://www.aliyun.com/zixun/aggregation/11208.html ">microsoft" Server Windows Azure Virtual ...

First, the initial understanding of large data seems to be overnight, big data becomes one of the most fashionable words in the IT industry. First of all, big data is not a completely new thing, Google's search service is a typical large data use, according to customer demand, Google real-time from the global mass of digital assets (or digital garbage) ...

Human activities are limited by the scientific and technological capabilities mastered. Although people can design beautiful stories in the field of ideology, in real life, these stories are difficult to use material form to present. Human civilization is not continuous, but developed in the form of a hierarchical structure, as described in the I Ching structure of the natural number model, although the natural numbers are continuous, but they are distributed in different layers. High-level civilization contains the technical characteristics of low-level civilization, but it also has some unique technical characteristics. Each level of product form is determined by its application of technical form, which indicates that every time the technical leather ...

May 17, in Chifeng, Inner Mongolia, several Chinese heavy steam users and local distributors reached a settlement agreement, Sichuan Panzhihua users Yang Wenkai, Inner Mongolia Baotou users Li Jing classmates and Li Guomin is still struggling to wait, do not know when their problems can be resolved.　　These users complained that China's heavy steam and dealers to join hands, the country Ⅱ car as a national Ⅲ car sold to them, resulting in the user face can not be a card or a road on the embarrassing situation of fines. Janeane, director of the China Consumer Protection Foundation, which has just returned from Tongliao, said he found 4 such cases in Tongliao. ...

HTC's recent frequent new products have failed to attract enough attention as other brands in the country, and HTC's situation has been very embarrassing, from madness to decline to being overlooked by the public. Very early out of the acquisition of news, more recently was the media gossip out to be TCL acquisition, Wang has come back for a year, in addition to the promotion of HTC no shortage of money will not sell the company, in the product also under the Kungfu. But is this angry nobleman able to make a comeback? Why is HTC reversing the situation? As an international product of the launch of the first Android phone ...