The tool looks very cool! But IMO you can't get an ER diagram from SQL since entities are fundamentally different from tables. They are certainly very similar, but SQL alone doesn't give you enough information to create an ER diagram.
That's not to say that the tool is useless or that diagrams of this sort are unhelpful. I'll admit I'm being pedantic and others will probably disagree.
> entities are fundamentally different from tables
Isn't the fact that they are _mostly_ interchangeable the foundational principle of hundreds of ORMs? Of course the DDL doesn't say much about the entity's lifecycle, but if the bar is set at representing its relationships, fields and cardinality as a graph, it seems sufficient?
ORMs are on a poor foundation. But I don't see the problem with this tool, it's just showing the tables.
To make parent’s point more exact: from Chen’s definition, these ER diagrams derived from SQL are the “physical” (most low-level) diagrams, you cannot recreate the “logic” or “conceptual” diagrams from it.
I guess nowadays few people care about this difference.
Few people ever cared about the difference.
Can you please elaborate on the differences? They are practically interchangeable, but conceptually there might be another layer on top of entities and relationships for somewhat richer semantics (like describing a relation, or additional annotations on the entity)
the use case for sql to er, is to study a database new to you
so the db already exist, but they have no er, and maybe even little docs
so it act more like an exploratory tool, ideally, it should allow you to create views and add notes, so you dont have to look at the full er at once, especially if the number of table is huge, and if many of those tables are missing foreign keys
Can you please elaborate? My understanding was that entities always have a 1:1 relationship with tables.
An example would be really helpful.
> entities are fundamentally different from tables
one man’s simplicity is another man’s headache