Leerschema

Leerschema is a term used in data modeling discussions to describe a compact, readable schema description language intended to express the structure, constraints, and semantics of data used in distributed systems.

Its design goals emphasize human readability, expressive power for structural relations and semantic constraints, and interoperability with existing data formats. Leerschema supports entities (types), attributes with primitive data types, optionality, multiplicity, and reference links between entities, with a focus on modularity and reusable components.

The syntax is declarative and aims for minimal boilerplate. Schemas can include annotations for documentation, constraints such as required fields, unique keys, and referential integrity. Serializations to JSON-like or YAML-like forms are commonly discussed, and several experimental parsers exist in academic or prototype tooling.

Typical applications include data integration, API contract design, knowledge graphs, and metadata catalogs. Example scenarios describe a Person with name and birthdate connected to Organizations, or an Article linked to an Author and a set of keywords. Leerschema is often proposed for schema evolution workflows.

Leerschema is not widely standardized and remains largely within research discussions or niche tooling. It competes with established standards such as JSON Schema, GraphQL SDL, and RDF Schema. Critics point to limited tooling and uncertain maturity, while proponents cite improved readability and composability. See also JSON Schema, GraphQL SDL, RDF Schema.