We’ve talked about how important it is to validate data before doing any reports. S**t in – S**t out.
With JSON columns it’s quite easy to make a mistake, we’ve already seen how filtering for empty JSON values could be misleading. Compare these 2 queries:
SELECT COUNT(*) FROM web_analytics.pageviews WHERE custom_parameters IS NOT NULL
SELECT COUNT(*) FROM web_analytics.pageviews WHERE custom_parameters::text != '{}'
Quite different numbers, right? Imagine we’d calculate conversion rate or something with these numbers, could be very dangerous.
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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. 