1-1 basic concepts of database

Basic concepts of database

database （database） It's for organizing 、 Warehouse for storing and managing data .

Common databases and classifications

Common databases are as follows ：

1. MySQL database （ At present, it is most widely used 、 The most popular open source free database ;（Community + Enterprise）
2. Oracle database （ charge ）
3. SQL Server database （ charge ）
4. Mongodb database （Community + Enterprise）

among ,MySQL、Oracle、SQL Server It belongs to traditional database （ Also known as ： Relational database or SQL database ）, The three design concepts are the same , The usage is similar

and Mongodb It belongs to a new database （ Also known as ： Non relational database or NoSQL database ）, To some extent, it makes up for the defects of the traditional database .

The data organization structure of traditional database

In a traditional database , The organizational structure of data is divided into database 、 Data sheet 、 data row 、 Field . this 4 Most of the components

In development , library 、 surface 、 That's ok 、 Field relationship

1. In actual development , In general , Each project corresponds to a separate database .
2. Different data , To store in different tables in the database . for example ： User data is stored in users Table design id、username、password These three fields .
3. What information is stored in each table , Determined by the field , for example ： We can users Table design id、username、password These three fields .
4. The rows in the table , Represents each specific piece of data .