#1060 - Duplicate column name 'id'

Question

Why I get #1060 - Duplicate column name 'id'

SELECT COUNT(*) FROM (SELECT * FROM `tips` `t` LEFT JOIN
tip_usage ON tip_usage.tip_id=t.id GROUP BY t.id) sq

Answer 1

Probably because the * in select * selects two columns with the same name from tip_usage and tips.

Answer 2

Probably it's because the inner select yields two columns with the name id. Since you are not using those columns, you can just change the select to:

SELECT COUNT(*) FROM (SELECT t.id FROM `tips` `t` 
LEFT JOIN tip_usage ON tip_usage.tip_id=t.id 
GROUP BY t.id) sq