PostgreSQL query joining a table and using json_agg() to get nested json output

Question

So i have to tables i would like to join but get an error.

The tables look like this. patterns table:

patternUuid	urlName	title
1b3d8a0f-2bc3-4c50-a00a-6cf99335dd20	card-fraud	Credit Card Fraud
04bdcd7b-d61b-45cc-b9ea-c2decc77c852	return-policy-fraud	Return Policy Fraud

members table:

id	memberId	patternsUuid
1	1	1b3d8a0f-2bc3-4c50-a00a-6cf99335dd20
2	2	1b3d8a0f-2bc3-4c50-a00a-6cf99335dd20
3	3	04bdcd7b-d61b-45cc-b9ea-c2decc77c852
4	3	04bdcd7b-d61b-45cc-b9ea-c2decc77c852

my sql that gives me an error

    SELECT "patternspatternUuid", "patterns.urlName", patterns.title, json_agg(members.memberId)
    FROM public.patterns
    JOIN members
    ON members.patternsUuid = patterns.patternUuid
    GROUP BY patterns.patternUuid

The error msg:

ERROR: column members.patternsuuid does not exist LINE 4: ON members.patternsUuid = patterns.patternUuid ^ HINT: Perhaps you meant to reference the column "members.patternsUuid".

At the end I what to call this query and make it and endpoint and a res in json to look like this:

    "patterns": [
    {
      "patternUuid": "1b3d8a0f-2bc3-4c50-a00a-6cf99335dd20",
      "title": "Credit Card Fraud",
       "urlName": "card-fraud"
      "description": "Lorem ipsum dolor sit",
      "members": [
        {
          "memberId": 1
        },
        {
          "memberId": 2
        }
      ],
    },

Answer 1

So my query ended up like this and works now

SELECT "patternUuid", "urlName", title, json_agg(m."memberId") as members
FROM public.patterns p
JOIN members m
ON m."patternsUuid" = p."patternUuid"
GROUP BY p."patternUuid"

Thanks for the answers as you can see, I had to use the quotes around the uppercase columns like this: members."memberId"