To understand the data model of a company or a product feature it usually helps to draw a diagram. The type of relationship between tables is reflected in the line that connects tables.
A simple line represents a one-to-one relationship. A dot highlights the table that has a foreign key. Here’s how we would represent the relationship between users and profile (user has one profile):
To highlight a one-to-many relationship we need to connect tables with a line that resembles a fork. Records from a table with a single line (...
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About SQL Habit
Hi, it’s Anatoli, the author of SQL Habit.
SQL Habit is a course (or, as some of the students say, “business simulator”). It’s based on a story of a fictional startup called Bindle. You’ll play a role of their Data Analyst and solve real-life challenges from Business, Marketing, and Product Management.
SQL Habit course is made of bite-sized lessons (you’re looking at one atm) and exercises. They always have a real-life setting and detailed explanations. You can immediately apply everything you’ve learned at work.