I have a data structure as following:
object1.array1[object2.array2[]]
I want to remove array2 from object2 or delete all array elements.
Is there a solution for this using AQL-Query?
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1 Answer
Demo document:
{
"foo": [
{"x": [1,2,3], "y": [4,5,6], "z": [7,8,9] },
{"hello": "world" }
],
"bar": true,
"_key": "0"
}
To remove foo[0].y ([4,5,6]) with AQL, here is a somewhat generic solution:
LET attr = "foo" // target top-level attribute
LET i = 0 // positive or negative index of target array element
LET subattr = "y" // sub-attribute to remove
LET doc = DOCUMENT("test/0")
LET before = SLICE(doc[attr], 0, i) // array elements before target
LET middle = UNSET(doc[attr][i], subattr) // remove sub-attribute from target element
LET after = i == -1 ? [] : SLICE(doc[attr], i+1) // elements after target
LET combined = APPEND(APPEND(before, middle), after)
UPDATE doc WITH { [attr]: combined } IN test
RETURN {NEW, OLD}
To remove "world" instead, simply change it to LET i = 1 and LET subattr = "hello".
2 Comments
Andre
Could you tell me, what in details happens here? LET after = i == -1 ? [] : SLICE(doc[attr], i+1) // elements after target
CodeManX
As long as
i is a positive, you can simplify it to LET after = SLICE(doc[attr], i+1). It gets the array elements from foo after i. I wanted it to work for negative values too, e.g.LET i = -1 to target the last element of foo (foo[-1].hello). The problem is that i+1 = -1+1 = 0, resulting in SLICE(doc[attr], 0), which would return all elements of foo. Therefore, I made use of the ternary operator ? : (cutt.ly/eepqE0M): if i equals -1 then return empty array (there are no elements after the last one), otherwise do usual slicing: i == -1 ? [] : SLICE(...)