SQL Join and Sorting | Dataford Interview Questions

Your question is SQL Join and Sorting. Start with the requirements and the two tables on the right.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

InMobi campaign reporting combines campaign records with their associated advertisers. Write a PostgreSQL query that joins these two tables and returns the campaign name and advertiser name twice: first in ascending campaign-name order, then in descending campaign-name order.

Requirements

Join inmobi_campaigns to inmobi_advertisers using the advertiser identifier.
Return only campaigns with a matching advertiser.
Produce one ascending result block followed by one descending result block.
Place NULL campaign names last within either sort direction, while retaining matched rows with NULL advertiser names.

Schema

inmobi_campaigns

Column	Type	Description
campaign_idPK	INTEGER	Unique campaign identifier
campaign_name	VARCHAR(150)	Campaign name
advertiser_id	INTEGER	Advertiser associated with the campaign

inmobi_advertisers

Column	Type	Description
advertiser_idPK	INTEGER	Unique advertiser identifier
advertiser_name	VARCHAR(150)	Advertiser name