#1057

One Primary Address

Design the addresses table for user addresses. It must store id as the primary key, user_id, and the is_primary flag; a user may have many addresses, but the database must prevent more than one row with is_primary = true for the same user_id.

Just CREATE/ALTER/DROP — no trailing SELECT needed.

Your query result will appear here

No starting schema

This task starts with no tables — you'll create them via CREATE TABLE.