Write DB schema (visual representation of database structure)

[zeroXbrock]

Design and document a high-level schema that represents DB fields and relationships.

Format: SQL-ish (think objects & styled arrows)

basic concepts:
proprietary
user: {api_key, itembase_address, email, password}

blockchain
item: {id, metadata}
_contract: {[items], owner}

AC:

• DB schema posted in Wiki
• schema represented with a picture