Left vs Right Joins | Dataford Interview Questions

In SQL, what is the difference between a LEFT and RIGHT join?

Write a PostgreSQL query that demonstrates the difference using properties and maintenance requests. Return every property, including properties without requests, and show NULL request fields when no match exists.

Output

One row per property and matching request, or one row for an unmatched property
Columns: property_id, address, request_id, status
Order by property_id, then request_id, with unmatched requests after matched requests

Schema

properties

Column	Type	Description
property_idPK	INT	Unique Invitation Homes property identifier
address	VARCHAR(255)	Property street address

maintenance_requests

Column	Type	Description
request_idPK	INT	Unique maintenance request identifier
property_id	INT	Property associated with the request
status	VARCHAR(30)	Current maintenance request status

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Problem