Legacy systems often skip foreign keys
Many inherited databases do not define every relationship explicitly, which makes the structure harder to trust and explain.
Legacy schema pain point
Understand databases even when foreign keys are missing.
Many inherited databases do not define every relationship explicitly. DataPilot ERD helps you inspect the schema visually, connect the dots faster, and review the model even when the database itself is incomplete.
SQL alone makes relationship tracing slow
When keys are incomplete, reading raw SQL is often the slowest way to rebuild the mental model of the database.
Visual context speeds up first understanding
A visual ERD workspace helps reviewers connect the dots faster, even when the source database is incomplete.
Import existing SQL
Start from the schema you already have instead of rebuilding the database structure manually.
Add and adjust relationships visually
Use the diagram as the review surface for inferred or agreed relationships when the database does not define them clearly.
Share one reviewable workspace
Keep one place where engineers, analysts, and reviewers can look at the same model and discuss it together.
FAQ
Questions about ERD without foreign keys.
Is this useful for legacy databases?
Yes. This page targets the exact situation where a schema exists but formal foreign keys are incomplete, inconsistent, or missing.
Does the tool change the source database?
No. The free ERD tool is for visual modeling and review in the browser.
Can I still document the assumed relationships?
Yes. Use the diagram and notes as the review surface for inferred or agreed relationships.