Programming Center for C # and database technology Basics-Database

Database, unknown, today we're going to the mystery of the database

　　1. The need to use a database

With the rapid development of Internet technology, as of 2013, the number of Internet users in China is nearly 600 million, and the number of netizens has led to the development of new industries such as online shopping, microblogging, and network video. Then, the resulting large amount of network data in a timely manner.

A lot of data is being generated, and what comes with it is how to store, retrieve, and manage them safely and efficiently. Effective storage of data, efficient access, easy sharing and security control issues have become a very important issue in the information age.

The use of databases can be efficient and well-organized storage of data, it is people can more quickly and easily manage data, mainly reflected in the following aspects.

(1) can be structured to store a large amount of data information, convenient for users to effectively search and access. The database can classify the data and can provide fast queries. For example, we go to Baidu to search for the data we want. In fact, Baidu Search is based on database and data classification technology to achieve the purpose of rapid search.

(2) can effectively maintain the consistency of data information, integrity, reduce data redundancy. Data stored in the database, can be good to save the data effectively, not be destroyed, and the database itself has the ability to avoid duplication of data, so as to reduce the data redundancy.

(3) can meet the sharing and security requirements of the application. Putting data in a database is also a security concern in many cases, for example, if you put all of your employees ' information in a database, you can only allow query and modification of employee information, and payroll information is only allowed to be viewed by financial personnel, which guarantees the security of the data.

(4) The database technology can facilitate intelligent analysis and generate new and useful information. For example, the supermarket stores the item sales information in the database, the monthly sales situation in fact determines the next month's purchase quantity, the results of the database query actually produced new data information. Data mining, on-line analysis technology has developed very fast in recent years, and the core meaning is to analyze useful new information from a pile of data.

　　　　2.SQL Server Introduction (main explanation)

(1) Business Edition (SQL Server Enterprise Edition)

The Enterprise Edition is the most comprehensive version that supports all of the features provided by SQL Server 2008 to meet the complex business needs of large enterprises.

(2) Standard Edition (SQL Server Edition)

The Standard Edition is suitable for small and medium-sized enterprises, which has an advantage over the Enterprise Edition.

(3) Workgroup Edition (SQL Server Workgroup Edition)

For small businesses that have no limits on the size and number of users, the Workgroup Edition is the ideal data management solution that can be used as a pre-segment Web server or as part of a department or branch office operation.

(4) Development version (SQL Server Developer Edition)

The development version covers all features of the Enterprise Edition, but is only allowed as a development and testing system and is not allowed as a production system.

　　　　3. Basic concepts of the database

(1) Entities and records

In the database concept, the entity is all objective, can be described things. For example, people, textbooks, tables and even the structure of textbooks, are objectively, can be described, these are called entities.

　　Data tables stored in a database, each row actually corresponds to an entity, in a database, usually called a record

Each column in a table, in a database, is often called a field .

(2) Database and database tables

Different types of records are organized together to form a table of the database, or a table is a collection of entities used to store specific data.

A database is a collection of tables, logically including data tables, tables that store relationships between tables, and various relational objects. Therefore, the description of the relationship is also part of the database.

　　　　4. Database management system and database system

Database Management System,dbms is a system software that consists of an interconnected set of data and a program that accesses data from an alien. This data set is often referred to as a database, the basic goal of the database management system is to provide a convenient and efficient access to database information environment.

Database System,dbs is an actual operational system, which can store, maintain and apply the data provided by the system, which is composed of storage medium, processing object and management system, and usually consists of software, database and database administrator.

Programming Center for C # and database technology Basics-Database