Entity definition in NestJS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an Entity in NestJS when using TypeORM?

An Entity is a class that maps to a database table. It defines the structure of the data and how it is stored in the database.

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How do you mark a class as an Entity in NestJS with TypeORM?

You use the @Entity() decorator above the class to tell TypeORM this class represents a database table.

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What decorator is used to define a primary key column in a NestJS Entity?

The @PrimaryGeneratedColumn() decorator is used to define a primary key that auto-increments.

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How do you define a regular column in a NestJS Entity?

Use the @Column() decorator above a class property to define a regular database column.

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Why is it important to define Entities in NestJS applications?

Entities help organize and manage how data is saved and retrieved from the database, making code easier to understand and maintain.

Which decorator marks a class as a database table in NestJS with TypeORM?

A @Entity()

B @Column()

C @Injectable()

D @Controller()

The @Entity() decorator tells TypeORM that the class is a database table.

What decorator is used to create an auto-incrementing primary key column?

A @PrimaryColumn()

B @Column()

C @PrimaryGeneratedColumn()

D @Generated()

@PrimaryGeneratedColumn() creates a primary key that auto-increments.

How do you define a normal column in an Entity?

A @Entity()

B @Column()

C @PrimaryGeneratedColumn()

D @Injectable()

The @Column() decorator defines a regular column in the database table.

What does an Entity class represent in NestJS with TypeORM?

A A service for business logic

B A middleware function

C A controller for routes

D A database table structure

An Entity class represents the structure of a database table.

Why should you use Entities in your NestJS app?

A To organize database data structure

B To handle HTTP requests

C To style the UI

D To manage user sessions

Entities organize how data is stored and retrieved from the database.

Explain how to define an Entity in NestJS using TypeORM and what decorators are essential.

Think about how a class becomes a table and how columns are defined.

Describe why Entities are important in a NestJS application that uses a database.

Consider how data is saved and retrieved in an app.