How to get values in mongdb - mongodb

Question

This is my my data in Mongodb
{
"d" : {
"results" : [
{
"slack_id" : "RAGHU#TN.COM",
"connector_id" : "GRECLNT900",
"sys_role" : "DEV",
"user_id" : "RAGHU"
},
{
"slack_id" : "RAGHU#TN.COM",
"connector_id" : "GRECLNT900",
"sys_role" : "PRD",
"user_id" : "RAGHU",
"question" : "What is your favorite color?",
"Answer" : "Orange"
},
]
}
}
If i am giving RAGHU#TN.COM. then i want display sys_role. Output like this[DEV, PRD]
I am trying this way
x = mydb.mycollection.distinct("sys-role")
But I get an empty array like [ ]

Answer 1

You have to treat the cursor as a reference(personally I see it as a reference in C), and then de-reference it to see the result.(What is inside the address)
For the specific column, here is the result from command prompt:
my_cursor = mydb.mycollection.distinct("sys-role")
for x in my_cursor:
print('{0}'.format(x['sys_role']))

Answer 2

The distinct operator is not inter-operatable thus it's hard to filter by slack_id first. I would recommande using aggregation pipelines.
Here is an example.
[
{
'$match': {
'slack_id': 'RAGHU#TN.COM'
}
}, {
'$group': {
'_id': 'slack_id',
'result': {
'$addToSet': 'sys_role'
}
}
}
]
With this pipeline, your sys_role set will be in the .result field.

Answer 3

Using Mongo aggregation query you will get required result set. Try this:
db.collection.aggregate([
{
"$match": {
"d.results.slack_id": "RAGHU#TN.COM"
}
},
{
$group: {
_id: "$d.results.slack_id",
sys_role: {
$push: "$d.results.sys_role"
}
}
}
])

Answer 4

db.getCollection("collection").aggregate(
// Pipeline
[
// Stage 1
{
$project: {
results: {
$filter: {
input: "$d.results",
as: "item",
cond: { $eq: [ "$$item.slack_id", 'RAGHU#TN.COM' ] }
}
}
}
},
// Stage 2
{
$unwind: {
path : "$results",
preserveNullAndEmptyArrays : false // optional
}
},
// Stage 3
{
$group: {
_id:'$results.slack_id',
sys_roles:{$addToSet:'$results.sys_role'}
}
},
]
);