Coming from SQL

    ArangoDB’s query language is called AQL. There are some similarities between bothlanguages despite the different data models of the database systems. The mostnotable difference is probably the concept of loops in AQL, which makes it feelmore like a programming language. It suits the schema-less model more naturaland makes the query language very powerful while remaining easy to read and write.

    To get started with AQL, have a look at our detailed.It will also help you to translate SQL queries to AQL when migrating to ArangoDB.

    You may also be interested in the white paperSwitching from Relational Databases to ArangoDBon our website!

    In traditional SQL you may either fetch all columns of a table row by row, using, or select a subset of the columns. The list of tablecolumns to fetch is commonly called select list:

    Since documents aren’t two-dimensional, and neither do you want to be limited toreturning two-dimensional lists, the requirements for a query language are higher.AQL is thus a little bit more complex than plain SQL at first, but offers muchmore flexibility in the long run. It lets you handle arbitrarily structureddocuments in convenient ways, mostly leaned on the syntax used in JavaScript.

    Composing the documents to be returned

    1. RETURN oneDocument
    1. [
    2.     {
    3.         "_id": "myusers/3456789",
    4.         "_key": "3456789",
    5.         "_rev": "14253647",
    6.         "firstName": "John",
    7.         "lastName": "Doe",
    8.         "address": {
    9.             "city": "Gotham",
    11.         "hobbies": [
    12.             { "name": "swimming", "howFavorite": 10 },
    13.             { "name": "biking", "howFavorite": 6 },
    14.             { "name": "programming", "howFavorite": 4 }
    15.         ]
    16.     }
    17. ]

    Return the hobbies sub-structure only:

    1. [
    2.     [
    3.         { "name": "swimming", "howFavorite": 10 },
    4.         { "name": "biking", "howFavorite": 6 },
    6. ]

    Return the hobbies and the address:

    1. RETURN {
    2.     hobbies: oneDocument.hobbies,
    3.     address: oneDocument.address
    4. }

    Return the first hobby only:

    1. RETURN oneDocument.hobbies[0].name
    1. [
    2.     "swimming"
    3. ]
    1. [
    2.     { "hobbies": ["swimming", "biking", "programming"] }

    More complex andobject manipulations can be done usingAQL functions and .