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Updating maps doesn't work using APOC library

kashu94
Node Clone

I have my edge attributes in the form of dictionaries as we'd refer in python or maps. I was testing the working of updating one such edge attribute using APOC library. So, let's say I have an edge attribute qty_dict = {'5':1, '10':2}

I was trying to update this by merging it with another such map, suppose {'5':2, '4':1, '3':3}.
So, when I merge, I would like to see the resultant dict as qty_dict =
{'5':3, '4':1, '3':3, '10':2}

Please have a look at what I've tried so far ...

1 ACCEPTED SOLUTION

glilienfield
Ninja
Ninja

I think you do not need to unwind map as ma and I think 'ma' on line 9 should be 'ma1' instead. As such, I think the following would be correct if it worked.

with apoc.convert.fromJsonMap("{'5':1,'10':2}") as map, apoc.convert.fromJsonMap("{'5':2,'4':1,'3':3}") as map1
unwind keys(map1) as ma1
call apoc.do.when(
    apoc.map.get(map,ma1,'False') = 'False',
    'return apoc.map.setKey(map,ma1,map1[ma1])',
    'return apoc.map.setValues(map,[ma1,map1[ma1]+map[ma1]])',
    {map:map, ma1:ma1, map1:map1}
)
yield value
return ma1, map1[ma1], value

It doesn't work because the value of map passed to the 'do.when' method on line 7 is always the original value of map, so it doesn't iteratively update the map.

You can try this approach. It seems to work:

with apoc.convert.fromJsonMap("{'5':1,'10':2}") as map, apoc.convert.fromJsonMap("{'5':2,'4':1,'3':3}") as map1
with [i in keys(map) where not i in keys(map1) | [i,map[i]]] as a,
[i in keys(map1) where not i in keys(map) | [i,map1[i]]] as b, 
[i in keys(map) where i in keys(map1) | [i,map[i]+map1[i]]] as c
return apoc.map.fromPairs(a+b+c)

Result:

Screen Shot 2022-12-01 at 2.06.24 PM.png

View solution in original post

2 REPLIES 2

glilienfield
Ninja
Ninja

I think you do not need to unwind map as ma and I think 'ma' on line 9 should be 'ma1' instead. As such, I think the following would be correct if it worked.

with apoc.convert.fromJsonMap("{'5':1,'10':2}") as map, apoc.convert.fromJsonMap("{'5':2,'4':1,'3':3}") as map1
unwind keys(map1) as ma1
call apoc.do.when(
    apoc.map.get(map,ma1,'False') = 'False',
    'return apoc.map.setKey(map,ma1,map1[ma1])',
    'return apoc.map.setValues(map,[ma1,map1[ma1]+map[ma1]])',
    {map:map, ma1:ma1, map1:map1}
)
yield value
return ma1, map1[ma1], value

It doesn't work because the value of map passed to the 'do.when' method on line 7 is always the original value of map, so it doesn't iteratively update the map.

You can try this approach. It seems to work:

with apoc.convert.fromJsonMap("{'5':1,'10':2}") as map, apoc.convert.fromJsonMap("{'5':2,'4':1,'3':3}") as map1
with [i in keys(map) where not i in keys(map1) | [i,map[i]]] as a,
[i in keys(map1) where not i in keys(map) | [i,map1[i]]] as b, 
[i in keys(map) where i in keys(map1) | [i,map[i]+map1[i]]] as c
return apoc.map.fromPairs(a+b+c)

Result:

Screen Shot 2022-12-01 at 2.06.24 PM.png

Thank you, it worked in a jiffy! 🙂