SQL Server example database Northwind (1) Entity Relationship

When learning Spss statistical analysis, EA Drawing Entity Relationship graphs, and PowerDesigner drawing database model diagrams, you cannot find a good instance. In actual work, the table structure used by the project belongs to the company's commercial confidential content, and the structure of the table is not familiar to everyone during communication; using a simple data model, such as Teacher, Student, and Class

When learning Spss statistical analysis, EA Drawing Entity Relationship graphs, and PowerDesigner drawing database model diagrams, you cannot find a good instance. In actual work, the table structure used by the project belongs to the company's commercial confidential content, and the structure of the table is not familiar to everyone during communication; using a simple data model, such as Teacher, Student, and Class

Learning Spss statistical analysis, EA paintingEntityLinkGraph and PowerDesignerDatabaseA model graph cannot find a good instance. In actual work, the table structure used by the project belongs to the company's commercial confidential content, and the structure of the table is not familiar to everyone during communication; when using simple data models such as Teacher, Student, and Class, creating tables and recording data is also a headache.ExampleDatabaseThis is exactly what everyone is familiar with and is ready for use.

Many books and tutorials use Northwind.DatabaseAs a model, but I have never understood it very well. I downloaded it and learned about it. Now I can take notes and learn about it in sequence using Spss.

EntityLink(E-R) Description:

The instance model consists of four parts: enterprise Employee (Employee), customer (Custom), Product and Order. The model roughly orders products from enterprise employees.

(1) Employee:

Including Region (East-West-North-South), Territory (Region, city), and Employee (Employee). Territory belongs to Region,LinkAssociation, rather than belonging, means that an employee can be associated with multiple regions, just like Michael Zhang, who is in the finance department and in the administration department.

1 Eastern
2 Western
3 Northern
4 Southern

(2) Customer m

(3) Product

Products are classified. All products with the same name and Category may have multiple suppliers, and different suppliers may have different unit prices.

(4) Order

There are multiple products under an order, and then a logistics is used for goods distribution.

CorrespondsEntityLink,DatabaseDesign, structure:

The employee table has its own Association. ReportTo is the direct leader of the employee, and the employee ID field is associated (the leader is also a company employee ).

After clarifying the data structure, you can analyze and process it.