What is required?

required is a keyword used in various contexts, most commonly in data serialization, validation, and schema definition languages (like JSON Schema, OpenAPI, and database schema definitions). It signifies that a particular field or property must be present in the data being described. If a required field is missing, the data is considered invalid according to the schema.

Here's a breakdown of its key aspects:

• Mandatory Presence: The core meaning of required is to enforce the existence of a field. Without it, the data is deemed incomplete or incorrect. See: https://www.wikiwhat.page/kavramlar/Mandatory%20Presence
• Validation: required is crucial for data https://www.wikiwhat.page/kavramlar/Validation processes. Tools and libraries use the required designation to automatically check incoming data against the schema and raise errors if required fields are absent.
• Schema Definition: In https://www.wikiwhat.page/kavramlar/Schema%20Definition, required is typically part of the schema specification. It is a declaration that helps define the structure and constraints of the data.
• Data Integrity: By enforcing the presence of critical data, required contributes to overall https://www.wikiwhat.page/kavramlar/Data%20Integrity.
• Error Handling: When validation fails due to a missing required field, it triggers https://www.wikiwhat.page/kavramlar/Error%20Handling mechanisms. These mechanisms notify the user or system that the data is invalid and needs to be corrected.
• Common Usage Examples:
  • JSON Schema: In JSON Schema, required is an array listing the names of properties that must be present in a JSON object.
  • OpenAPI (Swagger): OpenAPI uses required to specify which request parameters or schema properties are mandatory for an API operation.
  • Database Schema: Database schema definitions often have a NOT NULL constraint, which is conceptually similar to required.