Primary Key And Foreign Key In Database

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 ...

If a computer manufacturer, its database holds machine and accessories product information. The table used to save the whole product information is called pc; the table used to save the parts supply information is called parts. There is a field in the pc table, used to describe the type of CPU used in this computer; there is a field in the parts table, the description of the CPU model, we can think of it as a list of all CPU models. Obviously, the CPU used by this manufacturer must be a model that exists in the supply information sheet. At this time, two tables ...

With the rise of internet web2.0 websites, the relational database has become a very hot new field, the development of the non relational database products is very rapid. 　　But the traditional relational database in dealing with web2.0 website, especially the super large-scale and high concurrent SNS type web2.0 pure dynamic website already appeared to be powerless, has exposed many insurmountable problems, for example: 1, high configured--to the database higher concurrent reads and writes the demand WEB2.0 website to be based on user personalized information to generate real-time dynamic ...

What is a column-oriented open source distributed database HBase release time: 2012.04.16 14:41 Source: News and Author: HBase is a distributed, column-oriented open source database, developed by the Apache Foundation. Unlike a generic relational database, HBase is a database suitable for unstructured data storage. It is based on a column rather than a row based pattern. User stores data ...

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Xiaoman, one of China's Shiber. Every year from May 20 to 22nd, the sun reaches the yellow-diameter 60° as Xiaoman. The implication is that the grains of the Shahi crop begin to grout plump. Xiaoman season, everything is vigorous, rapid growth, breeding infinite hope. Shenzhen Xiaoman Technology Co., Ltd. (Xiaoman Technology) is an innovative Internet company designed to provide SaaS services and productivity tools for businesses through cloud computing. Mainly for small and medium-sized enterprises, to help customers improve their enterprise management level, improve sales force, resulting in sustained growth in performance, so that enterprises more onstage ...

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The intermediary transaction SEO diagnoses Taobao guest Cloud host Technology Hall 1. What keyword do you want to do well? As long as you can think of Chinese words can be used as a key word. Site do not do more than one keyword, a number of keywords too dispersed, a site to do one to two keywords is good, so easy to do up. Do site content can pick a good keyword, if this keyword no one to do, the unit price is high, it would be cool to death. But this is difficult, because almost all the keywords are discovered, can only pick some small competition, can be based on this keyword ...

The concept of large data, for domestic enterprises may be slightly unfamiliar, the mainland is currently engaged in this area of small enterprises. But in foreign countries, big data is seen by technology companies as another big business opportunity after cloud computing, with a large number of well-known companies, including Microsoft, Google, Amazon and Microsoft, that have nuggets in the market. In addition, many start-ups are also starting to join the big-data gold rush, an area that has become a real Red sea. In this paper, the author of the world today in the large data field of the most powerful enterprises, some of them are computers or the Internet field of the Giants, there are ...