arangodb/Documentation/Books/Drivers/js-reference-database-aql-user-functions.md

layout	description
default	These functions implement theHTTP API for managing AQL user functions

Managing AQL user functions

These functions implement the HTTP API for managing AQL user functions.

database.listFunctions

async database.listFunctions(): Array<Object>

Fetches a list of all AQL user functions registered with the database.

Examples

const db = new Database();
const functions = db.listFunctions();
// functions is a list of function descriptions

database.createFunction

async database.createFunction(name, code): Object

Creates an AQL user function with the given name and code if it does not already exist or replaces it if a function with the same name already existed.

Arguments

• name: string

  A valid AQL function name, e.g.: "myfuncs::accounting::calculate_vat".

• code: string

  A string evaluating to a JavaScript function (not a JavaScript function object).

Examples

const db = new Database();
await db.createFunction(
  'ACME::ACCOUNTING::CALCULATE_VAT',
  String(function (price) {
    return price * 0.19;
  })
);
// Use the new function in an AQL query with template handler:
const cursor = await db.query(aql`
  FOR product IN products
  RETURN MERGE(
    {vat: ACME::ACCOUNTING::CALCULATE_VAT(product.price)},
    product
  )
`);
// cursor is a cursor for the query result

database.dropFunction

async database.dropFunction(name, [group]): Object

Deletes the AQL user function with the given name from the database.

Arguments

• name: string

  The name of the user function to drop.

• group: boolean (Default: false)

  If set to true, all functions with a name starting with name will be deleted; otherwise only the function with the exact name will be deleted.

Examples

const db = new Database();
await db.dropFunction('ACME::ACCOUNTING::CALCULATE_VAT');
// the function no longer exists