Working with schemas

Validate a schema

Validation checks a document without opening a database connection. Run it before rendering or deployment.

From the command line 

duburl schema validate schema.yaml
duburl schema validate schema.yaml --output-format json

The JSON Schema checks document shape and local constraints. The document validator additionally checks relationships such as missing columns, duplicate identities, incompatible facets, and view dependency cycles.

From .NET

Install DubUrl.Schema.Documents, then read and validate the document:

using DubUrl.Schema.Documents;

var document = new SchemaDocumentReader().Read("schema.yaml");
var validator = new SchemaDocumentValidator();
var diagnostics = validator.Validate(document);
foreach (var diagnostic in diagnostics)
    Console.WriteLine($"{diagnostic.Code} at {diagnostic.Path}: {diagnostic.Message}");

Reading infers the format from the filename. Malformed input is reported with source/location information by SchemaDocumentException. Validation accumulates diagnostics without mutating the DTO; each diagnostic has a stable SDV... code, severity, message, and document path.

SchemaDocumentMapper always validates before mapping and throws SchemaDocumentMappingException when the document is invalid. Explicit validation is useful when you want to show diagnostics to a user before mapping.

Next steps