Database design You know, you're worth it.

Long time no see everyone, Small series returned, I know you must think of me, yes I know, well, this return is to bring new knowledge, we must listen carefully, will benefit lifelong Oh!

(1) What is database design?

Database design is the process of planning and structuring the relationship between data entities in a database.

Database designers are very important, good database design will be efficient, easy to expand further, making application development easier.

(2) Now that we're designing the database, we need to know its steps.

Collect information, identify entities, identify the details that each entity needs to store, and identify relationships between entities.

(3) Entity-Relationship model

Entity: refers to an entity in the real world that has characteristics or attributes of other things and is associated with other entities.

Properties: A feature that can be understood as an entity.

Contact: Refers to the relationship between two or dawn entities.

(4) mapping cardinality: One-to-many, many-to-many, many-to-more.

(5) Entity Relationship Diagram

(6) Relational data graph mode: A relationship that is described as a collection of property names becomes a relational pattern.

(7) Logical design--Drawing Database Model diagram

First step: Create a new Database model diagram

Step Two: Add entities

Step three: Add data columns and corresponding properties

Fourth step: Add a mapping relationship between entities

Here's what we're going to focus!!!!! Enlarge your eyes see clearly, see Clearly, I do not tell them the ordinary people oh ~

Here is the most important understanding of the most colloquial paradigm of painstaking writing:

The above is a simple understanding of database design, I believe that if you can understand the future learning database will be a great help oh!~

Database design You know, you're worth it.