Get subtotals with ROLLUP+GROUP BY

𝙍𝙊𝙇𝙇𝙐𝙋 generates extra rows that represent the subtotals.

For example…

To get the sum of spending of each user, you typically GROUP BY user_id and SUM spend.

Want to get the sum of ALL users in the same result? Try ROLLUP.

📌 The syntax is here.
𝚂𝙴𝙻𝙴𝙲𝚃
𝚄𝚜𝚎𝚛_𝚒𝚍, 𝚂𝚄𝙼(𝚜𝚙𝚎𝚗𝚍)
𝙵𝚁𝙾𝙼
𝚄𝚜𝚎𝚛𝚜
𝙶𝚁𝙾𝚄𝙿 𝙱𝚈 𝚁𝙾𝙻𝙻𝚄𝙿(𝚞𝚜𝚎𝚛_𝚒𝚍)

The result will contain a NULL user_id which contains the sum of spend of all users.

🚀 In the demo below, we do a roll-up of two aggregation columns, and show the use of a partial roll-up. Check it out.

Bonus point if you can spot the mistake in the demo below.