typeORM

What does this property of an entity have as database datatype? @Column("text") description: string` It’s text (not varchar 255)

What does this property of an entity have as database datatype? @Column("double") views: number double, not integer

What is the name of the default superuser created by postgres? postgres

explain the following line of code: docker exec -it postgres psql -U postgres -i interactive mode -t allocates a pseudo-terminal to enable terminal like experience postgres is name of container psql is the interactive terminal (command line tool) used to execute SQL commands. -U specifies the user to connect to db.

explain the following line of code: ALTER USER username WITH SUPERUSER; Makes username a superuser, assuming they exist as a user with auth details.

How do you create a user after connecting to the postgresql instance? CREATE USER userName WITH PASSWORD password;

If I wanted to grant a user the right to connect to a database, what would the command look like? GRANT CONNECT ON DATABASE your_database TO read_only_user;

After granting connection permission to a user to a database, how would I grant them the right to see it’s schema? GRANT USAGE ON SCHEMA public TO read_only_user;

after granting a user permission to see the schema of a table, how would you allow the user to read entries from the table? ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO read_only_user;

What is the relationship between entities and repositories in typeORM? Each entity has its own repository which handles all operations with its entity.

What does the following code do inside an entity?

@OneToOne(() => Photo) 
@JoinColumn() 
photo: Photo

Creates a one to one relationship between the entity and the Photo entity, and specifies that the relationship is owned by this entity.

Can we put join column on both sides of a bidirectional relationship? No, the side that has it owns the relationship and has a foreign key.

What does a one to one bidirectional relationship look like on photo and photometadata, on both sides? on metadata:

@JoinColumn() 
photo: Photo

on photo:

metadata: PhotoMetadata

What is the relation wrapper used for in ESM? To prevent circular dependencies.