SQL Tables
Basics
You can easily diagram entity-relationship diagrams (ERDs) in D2 by using the sql_table shape. Here's a minimal example:
Each key of a SQL Table shape defines a row. The primary value (the thing after the colon) of each row defines its type.
The constraint value of each row defines its SQL constraint. D2 will recognize and shorten:
| constraint | short |
|---|---|
| primary_key | PK |
| foreign_key | FK |
| unique | UNQ |
But you can set any constraint you'd like. It just won't be shortened if unrecognized.
You can also specify multiple constraints with an array.
If you'd like to use a reserved keyword, wrap it in quotes.
Foreign Keys
Here's an example of how you'd define a foreign key connection between two tables:
When rendered with the TALA layout engine or ELK layout engine, connections point to the exact row.
Example
Like all other shapes, you can nest sql_tables into containers and define edges
to them from other shapes. Here's an example: