PRACTICAL FIELD GUIDE
Use a unique field without confusing it with validation
A unique constraint prevents duplicate stored values according to the database's comparison behavior. It does not automatically normalize user input or define all business equivalence rules.
MCPBackend editorial team · · Examples are illustrative
Put it into practice
- Decide the canonical representation of the field before adding uniqueness.
- Inspect and resolve existing duplicates through a reviewed process.
- Handle a duplicate response in the application and test case, whitespace and concurrent submissions.
What this looks like
ILLUSTRATIVE EXAMPLE
Two forms submit the same external reference. A unique field can prevent duplicate storage, while the UI explains that the reference already exists.
A boundary to keep clear
Do not assume differently formatted strings compare as the same business value. Normalize intentionally and test the database behavior.
MCPBackend context
MCPBackend stores each project's data in SQLite and exposes supported tables through generated REST endpoints. Use the schema tools and dashboard for supported changes. The design examples here are patterns to adapt, not claims that the API exposes every SQLite feature or arbitrary SQL.
Take the next step
Inspect the current project contract, try the change with disposable data, and verify the result through the same credentials your app will use. Record the expected response and one denied-access case before release.
Sources and further reading
These references explain the underlying protocols and design principles. For supported MCPBackend operations and exact request shapes, inspect your project’s generated API contract.