SQL Relationships

📖 Relationships

Questions

1. What is the difference between a primary key and a foreign key

2. What is an Alias?

3. Demonstrate how you would query a join statement that would get all of a doctors patients from the following collections:

CREATE TABLE doctors (
  id INT NOT NULL AUTO_INCREMENT,
  -- CODE OMITTED
  PRIMARY KEY (id)
)

CREATE TABLE patients (
  id INT NOT NULL AUTO_INCREMENT,
  -- CODE OMITTED
  PRIMARY KEY (id)
)

CREATE TABLE doctors (
  id INT NOT NULL AUTO_INCREMENT,
  doctorId INT NOT NULL,
  patientId INT NOT NULL,

  FOREIGN KEY (doctorId)
    REFERENCES doctors(id),
  FOREIGN KEY (patientId)
    REFERENCES patients(id),
)

Afternoon Assignment Link

Repo

Identify at least 1 takeaway from today’s assignment