Database Overview
1 What is the data (Data)
Symbol Symbol description of things called data record, describe things can be both digital, it can be text, pictures, images, sounds, language, data from a variety of forms, they can be digitally stored after computer
In a description of a computer object, it is necessary to extract the typical characteristics of things, the composition of a record, the file is equivalent to a single line, such as:
1 egon,male,18,1999,山东,计算机系,2017,oldboySimply a record and did not make any sense, if we press the comma as the separator, followed by the definition of the meaning of each field, a title equivalent to the definition of the table
1 name,sex,age,birth,born_addr,major,entrance_time,school #字段
2 egon,male,18,1999,山东,计算机系,2017,oldboy #记录So that we can understand egon, male gender, age 18 years old, born in 1999, the birthplace of Shandong, in 2017 admitted to the Department of Computer old boy
2 What is the database (DataBase, referred to as DB)
Database data that is stored in the warehouse, the warehouse is only on a computer storage device, and the data is stored in a certain format
People used the data stored in the file cabinet, and now the huge amount of data, is no longer applicable
Long-term database is stored in the computer, organized, sharable data can be.
Data in the database according to certain organizational data model, described and storage, has a smaller redundancy, higher data independence and easy scalability, can be shared for various users
3 What is a database management system (DataBase Management System referred to as DBMS)
In the understanding of the concept of Data and DB after, how to organize and store scientific data, how to efficiently obtain and maintain data become critical
This system uses a database management system software ---
如MySQL、Oracle、SQLite、Access、MS SQL Server
mysql is mainly used for large portals, such as Sogou, Sina, its main advantage is the open source because open source database is free, he is now Oracle's products.
oracle is mainly used in banks, railways, airports and so on. The database is powerful, high software costs. Is Oracle's products.
sql server is a Microsoft product, mainly used in medium and large companies, such as Lenovo, Founder and so on.
4 relational database servers, data management systems, databases, tables and records (focus on understanding !!!)
Record: 132424523422 Hailong (composed of a plurality of record information fields, i.e., a line content file)
Table: student, scholl, class_list (ie, file)
Database: oldboy_stu (ie folder)
Database management systems: as mysql (a software)
Database server: A computer (higher memory requirements)
to sum up:
Database server: - database management software running
Database management software: Management - Database
Database: the folder to organize your files / tables
Table: the file used to store a multi-line / multiple records