查询ArangoDB 3.1中的日期

Question

As I understood, ArangoDB 3.1 now supports date type as part of their new internal storage format VelocyPack. How I am supposed to use fields with date type in AQL queries (eg FILTER)? Looks like the documentation is not yet updated for date type fields: https://docs.arangodb.com/devel/AQL/Functions/Date.html

Can someone provide an AQL query example? Something like

FOR p IN person FILTER p.birthday == '2016-11-04' RETURN p

where the field p.birthday is of date type?

Answer 1

Because VelocyPack is primary used as ArangoDBs internal storage format, the additional VelocyPack types are currently not supported by AQL, the shell or the web-ui. They all have to use json for processing.

Currently the only way to create a document with a date type is over the Java-Driver (version 4.1.0). The driver is also the only possibility to get VelocyPack as a result from an AQL query. Every other implementation returns you json naturally without the additional VelocyPack types.

Apart from this the AQL-date functions do not support VelocyPack date type at the current state of development.

Answer 2

ArangoDB uses VelocyPack as the internal storage format since ArangoDB version 3.0. VelocyPack has a Date datetype as well as some other datatypes which are not present in JSON.

But even though VelocyPack is used as the internal storage format in ArangoDB, all external APIs of ArangoDB still are JSON-based, meaning they only support the datatypes natively supported by JSON (null, boolean, number, string, array, object).

Support for more (non-JSON) datatypes is on the roadmap, but is not there yet as of ArangoDB 3.1. Supporting more datatypes requires writing some internal wrapper functions for these datatypes plus make all the AQL operators work correctly with them.

So in version 3.1 the options for saving date values are still to use datetime strings (eg in ISO8601 format such as 2016-11-10T14:08:20.236Z ) or to use number values for storing timestamps.