datavelden

Datavelden, or data fields, are the discrete units of information stored in a data record. They define what kind of data is captured, held, and described for each entity, and they appear in schemas, data dictionaries, and data-entry forms. In relational databases, datavelden correspond to columns in a table, with each row representing a record.

A dataveld typically specifies several attributes: a name, a data type (such as string, integer, date, boolean, or decimal), and optional properties like length, precision, and constraints. Common constraints include NOT NULL, UNIQUE, and CHECK rules, as well as default values. Datavelden are designed to reflect business concepts, support data validation, and enable accurate querying and reporting. They are closely linked to data modeling concepts like attributes and to the fields found in forms and user interfaces.

Metadata plays a key role in describing datavelden. A data dictionary or metadata repository records each field’s definition, allowed values or ranges, units of measure, and data lineage. Consistent naming, data types, and documentation help maintain data quality and interoperability across systems.

Examples include a Customers table with CustomerID (integer, primary key, not null), Name (string, up to 100 characters), Email (string, unique, not null), and BirthDate (date, nullable); and a product form with fields like Price (decimal) and InStock (boolean). In practice, datavelden enable data capture, storage, querying, reporting, and integration, while requiring governance to ensure consistency and reliability across datasets.