How to count number of elements with AQL?

Question

I need to count elements that was in result of SQL query: db._query('FOR v in visitors FILTER v.ip == "127.0.0.1" return COUNT(v.guid) ')

This request is return my a length of every GUID, but I need to get total number of GUIDs for example: 2.

Convey

Did the answer fullfill your needs? If not, whats missing? If, can you mark it accepted? – Crutchfield

Answer 1

You need to use the result of the query as input for the COUNT function, and then RETURN this result.

You can replace the RETURN value of the actual query by 1 for performance reasons:

RETURN COUNT(FOR v IN visitors FILTER v.ip == "127.0.0.1" RETURN 1)

Crutchfield

This didn't work for me, I had to use LENGTH rather than COUNT. – Romansh

COUNT is actually an alias of LENGTH, so you're invoking the same code path inside of the ArangoDB server. Whatever you changed in your query must have been more than swapping the both to make it work. – Crutchfield

Mhh. Nope. Just changing that one word. If I use COUNT I get [ArangoError 1540: usage of unknown function 'COUNT()' (while parsing)]. Maybe the alias was introduced in a version newer than the one I use. – Romansh

The currently supported versions don't show that behaviour. Maybe you should upgrade? Which version are you running? Maybe a github issue would be better to continue this. – Crutchfield

Answer 2

Version from 2022!

FOR m IN messages 
FILTER DATE_HOUR(m.date) == 3
COLLECT WITH COUNT INTO length
RETURN length

Granddaughter

Great, at last they have this functionality. :) – Staciestack