Tricky~20min
The Meter Reading That Went Backwards
6 meters logged a reading lower than their previous one with no replacement on file — usage can't go backward under normal billing, which points to tampering or a bad read. 10 other meters also show a lower reading, but those had a legitimate meter swap recorded on that same row.
Tables you'll query
metersmeter_readings
What you'll learn
JOINs