*** title: "Calculated" generated: true --------------- ## Calculated Used to define calculated entity getters. The decorator simply attaches an array of "calculated" property names to the entity's prototype. This array is then used by the [CalculatedPropertySubscriber](/current/core/reference/typescript-api/data-access/calculated-property-subscriber#calculatedpropertysubscriber)to transfer the getter function from the prototype to the entity instance. ```ts title="Signature" function Calculated(queryInstruction?: CalculatedColumnQueryInstruction): MethodDecorator ``` Parameters ### queryInstruction \CalculatedColumnQueryInstruction`} /> ## CalculatedColumnQueryInstruction Optional metadata used to tell the [ListQueryBuilder](/current/core/reference/typescript-api/data-access/list-query-builder#listquerybuilder) & [Relations](/current/core/reference/typescript-api/request/relations-decorator#relations) decorator how to deal with calculated columns when sorting, filtering and deriving required relations from GraphQL operations. ```ts title="Signature" interface CalculatedColumnQueryInstruction { relations?: string[]; query?: (qb: SelectQueryBuilder) => void; expression?: string; } ```

### relations \ If the calculated property depends on one or more relations being present on the entity (e.g. an `Order` entity calculating the `totalQuantity` by adding up the quantities of each `OrderLine`), then those relations should be defined here. ### query \) => void`} /> ### expression \