AQB: referencing index in array

[Julian May]

Hey

I'm having problems using a declared variable as index for an array within a document.

In AQL i can write

LET myIdx = POSITION(['a','b','n','q'],'n', true)

LET changed = ((changeIdx > -1) ? MERGE(oldDocument.collection, otherDocument.collection[myIdx]) : e) 

RETURN changed

but aqb.ref('otherDocument.collection[myIdx]') fails with the error 

"message": "Not a valid simple reference: changes[myIdx]"

How do i use a reference value as index in a reference array?

Thanks :)

[Alan Plum]

Hi Julian,

the easiest way to write AQL in JS is actually to use the aqlQuery template handler provided in ArangoDB and the JS driver:

https://github.com/arangodb/arangojs#aqlquery

https://docs.arangodb.com/cookbook/MultilineQueryStrings.html#es6-template-strings

The reason you're seeing the error is that aqb.ref only supports "simple references", i.e. variable names and property expressions using the dot operator.

If you want to use the square brackets you can do so using the "get" method:

aqb.ref('otherDocument.collection').get('myIdx')

https://github.com/arangodb/aqbjs#property-access

This returns an expression that evaluates to "otherDocument.collection[myIdx]" in AQL.

Cheers,

Alan

[Julian May]

Thanks!