Filtering a nested array with scan in dynamodb-CodePudding

I trying to work out the DynamoDB scan with the nested array. I trying to get the user details base on the survey id in the nested array, My table value is like this.

{
 "id": "28009dd8-5802-20f5-c7c9-af53e710ac91",
 "user": {
  "address1": "1, Park avenue",
  "address2": "Austin",
  "birthDate": "1999-01-01",
  "city": "Austin",
  "contact": "9876543210",
  "country": "1",
  "email": "[email protected]",
  "emgContact": "2",
  "empStatus": "1",
  "ethnicity": "5",
  "firstName": "Rajmohan",
  "gender": "male",
  "highLevelEduc": "2",
  "image": "",
  "lName": "V",
  "mName": "",
  "nationality": "1",
  "relationalStatus": "1",
  "state": "43",
  "telephone": "9876543210",
  "zipCode": "70031"
 },
 "survey": [
  {
   "id": "e8de014a-22c1-12bf-4653-577c8031138",
   "email": "[email protected]",
   "method": [
    "email"
   ],
   "name": "Rajmohan",
   "onDemand": "yes",
   "pollSchedule": "None",
   "pollTarget": "Educator",
   "telephone": "963696369",
   "user_id": "413ca05f-ed91-50e7-1974-3e0280ca4a3d"
  },
  {
   "id": "5f4db059-c8a3-e673-iygk-d857425e1077",
   "created_at": 1674459043374,
   "email": "[email protected]",
   "method": [
    "email"
   ],
   "name": "New testing",
   "onDemand": "yes",
   "pollSchedule": "None",
   "pollTarget": "Educator",
   "telephone": "963696369",
   "user_id": "413ca05f-ed91-50e7-2635-3e0280ca4a3d"
  }
 ],
 "summary": "test",
 "user": "413ca05f-ed91-8k8y-2635-3e0280ca4a3d"
}

and my scan syntax is like that.

var param = {
        TableName: 'user',
        FilterExpression: 'contains(#survey.#id,:id)',
        ExpressionAttributeNames: {
            '#survey': 'survey',
            '#id':'id'   
        },
        ExpressionAttributeValues: {
            ':id': id
        },
      }

But I can't get the value. My point is based on the survey id I need to get the value of the user.

CodePudding user response：

You cannot do what you're attempting, you would need to pass in the full value of the map which would be quite difficult to do i'm sure.

Using a list of maps

You need to know the entire map value when using contains function, as you are asking if the map is contained in the list, not if a string is contained in the map:

var mymap = {
   "id": "e8de014a-22c1-12bf-4653-577c8031138",
   "email": "[email protected]",
   "method": [
    "email"
   ],
   "name": "Rajmohan",
   "onDemand": "yes",
   "pollSchedule": "None",
   "pollTarget": "Educator",
   "telephone": "963696369",
   "user_id": "413ca05f-ed91-50e7-1974-3e0280ca4a3d"
  }

var param = {
        TableName: 'user',
        FilterExpression: 'contains(#survey,:mymap)',
        ExpressionAttributeNames: {
            '#survey': 'survey'
        },
        ExpressionAttributeValues: {
            ':mymap': mymap
        },
      }

Using nested maps

You should structure your list as a map:

 "survey": {
 "e8de014a-22c1-12bf-4653-577c8031138":{
   "email": "[email protected]",
   "method": [
    "email"
   ],
   "name": "Rajmohan",
   "onDemand": "yes",
   "pollSchedule": "None",
   "pollTarget": "Educator",
   "telephone": "963696369",
   "user_id": "413ca05f-ed91-50e7-1974-3e0280ca4a3d"
  },
  "5f4db059-c8a3-e673-iygk-d857425e1077": {
   "created_at": 1674459043374,
   "email": "[email protected]",
   "method": [
    "email"
   ],
   "name": "New testing",
   "onDemand": "yes",
   "pollSchedule": "None",
   "pollTarget": "Educator",
   "telephone": "963696369",
   "user_id": "413ca05f-ed91-50e7-2635-3e0280ca4a3d"
  }
 }

var id = "5f4db059-c8a3-e673-iygk-d857425e1077"
var param = {
        TableName: 'user',
        FilterExpression: 'attribute_exists(#survey.#id)',
        ExpressionAttributeNames: {
            '#survey': 'survey',
            '#id': id 
        }
      }