Not properly a database schema dialect but using the Azimutt JSON Schema structure, you will be able to define your database structure in JSON and convert it to other dialects.

The JSON format is defined here, you can suggest improvements.

It's a Markdown-inspired text definitions that generate flowcharts diagrams. It can be used to generate Entity-Relationship diagrams, and even has a Live Editor.

Have any issue? You can update it here.