Hey everyone! 👋 It's been a while since I posted here. Over the past few days, I've been revisiting SQL from the ground up—not just solving problems, but understanding why different SQL concepts exist and when they should be used. One topic that confused me (and many beginners) was correlated subqueries . You may have seen queries like this: SELECT ... FROM table1 t1 WHERE EXISTS ( SELECT * FROM table2 t2 WHERE t2 . id = t1 . ...