Update nested json array fields in Couchbase - couchbase

Question

Please share your thought on how to update on below field
"UserList": [
{
"userAge":33,
"empID":32,
"empSal":120000,
"userDept":{
"deptId":1,
"deptEmpCount":10,
"deptNo":2
}
},
{
"userAge":33,
"empID":31,
"empSal":120000,
"userDept":{
"deptId":1,
"deptEmpCount":10,
"deptNo":2
}
}
]
want to update deptEmpCount and deptId based on empID.
I also want to remove objects based on empID.

Answer 1

Addition to Roi Katz answer updating more than one array field and removing from object from array.
To update array element you must use update-for syntax and last example https://docs.couchbase.com/server/current/n1ql/n1ql-language-reference/update.html
Update 2 fields you must use SET clause with each has its own FOR.
Unset you can use same way.
UPDATE default AS d
SET u.userDept.deptEmpCount = u.userDept.deptEmpCount+1 FOR u IN d.UserList WHEN u.empID = 31 END,
u.userDept.deptId = 2 FOR u IN d.UserList WHEN u.empID = 31 END
UNSET u.userDept.deptNo FOR u IN d.UserList WHEN u.empID = 31 END
WHERE ...;
To remove object from the ARRAY you can construct new array and assign it
UPDATE default AS d
SET d.UserList = ARRAY u FOR u IN d.UserList WHEN u.empID != 31 END
WHERE ...;
If you want to do complex operations on ARRAY by using subquery expression (FROM clause of subquery using expression from the parent) and able to do complete SQL on ARRAY as source of documents.
Example: Removing empID = 31 and sorting array by empID and limiting size of array to 5.
UPDATE default AS d
SET d.UserList = (SELECT u.*
FROM d.UserList AS u
WHERE u.empID != 31
ORDER BY u.empID
LIMIT 5)
WHERE ...;
To Add new object to UserList
UPDATE default AS d
SET d.UserList = ARRAY_APPEND(d.UserList, { "userAge": 34, "empID": 33, "empSal": 120000, "userDept": { "deptId": 1, "deptEmpCount": 10, "deptNo": 3 } })
WHERE ...
To Add new object to UserList if not there, if there update it.
UPDATE default d
SET d.UserList = (CASE WHEN (FIRST u FOR u IN d.UserList WHEN u.empID = 33 END) IS MISSING
THEN ARRAY_APPEND(d.UserList,
{ "userAge": 34, "empID": 33, "empSal": 120000, "userDept": { "deptId": 1, "deptEmpCount": 10, "deptNo": 3 } })
ELSE d.UserList END
END),
u.userDept.deptId = 2 FOR u IN d.UserList WHEN u.empID = 33 END
WHERE ....

Answer 2

First I would like to clarify, CouchDB is not Couchbase :)
UPDATE myBucket1 AS d
SET o.empSal = "120001" FOR o IN d.UserList WHEN o.empID = 32 END
Now in order to remove, you just do something similar, just use the unset keyword.
presume you have another field in the array called "dummy".
UPDATE myBucket1 AS d
UNSET o.dummy FOR o IN d.UserList WHEN o.empID = 32 END
as far as i'm aware since we are talking on array, you can't currently combine them both.
please note, that you should specify a where clause. Since you have only 1 document it doesn't really matter, but in real life- you should.
please also look at the documentation for further instructions
https://docs.couchbase.com/server/current/n1ql/n1ql-language-reference/update.html