Many-to-many Memes

When you're designing a database schema but the requirements are... let's say "politically sensitive." Someone took an ERD diagram and decided to document relationships that probably shouldn't be in production. The many-to-many relationship symbol in the middle is doing some heavy lifting here. In database design, that diamond shape represents a junction table connecting two entities—because apparently some connections require their own dedicated table to store all the "metadata." Nothing says "normalized database design" quite like controversial real-world relationships mapped to crow's foot notation. Your DBA is definitely not approving this pull request.

The classic "just one small change" that breaks your entire data model. You design a perfect database with a unique constraint ensuring each user belongs to exactly one organization. The requirements were crystal clear. You even got it in writing. Then suddenly, the user who SWORE the relationship would "always be N:1" comes back asking if users can belong to multiple organizations. That look of horror is every database architect who now has to create a junction table, update all the queries, and pretend they're not dying inside. Next time, just assume every relationship is many-to-many from the start and save yourself the trauma.