firebase realtime database query

Question

I have the following structure:

{
  "Campaign" : {
    "-KtghP_NMOFrjN_RrI6f" : {
      "Projects" : {
        "-Kz5g4j8dKgxtqQsPfN1" : {
          "createByName" : "Michal",
          "profileId" : "-KtlDwI3Bq4Bi7R23kya"
        },
        "-KzGCaLblTxzu4Nje15Z" : {
          "createByName" : "Roy",
          "profileId" : "-Kxx_egu9h4GOrxqM1nB"
        }
      }
    },
    "-KyjE0HPNSg27Kpurq8l" : {
      "Projects" : {
        "-KzBUZBsI947HckV296O" : {
          "createByName" : "Roy",
          "profileId" : "-Kxx_egu9h4GOrxqM1nB"
        }
      }
    }
  },
  "UserProfile" : {
    "-Kxx_egu9h4GOrxqM1nB" : {
      "MyProjects" : {
        "-KzGC3Yn4bAAorcwDhUT" : {
          "CampaignId" : "-KyjE0HPNSg27Kpurq8l",
          "projectId" : "-KzBUZBsI947HckV296O"
        },
        "-KzGCaeTqMm_g1Jq6u6i" : {
          "CampaignId" : "-KtghP_NMOFrjN_RrI6f",
          "projectId" : "-KzGCaLblTxzu4Nje15Z"
        }
      },
      "firstName" : "roy"
    }
  }
}

i have the profile id.

I need to get the different projects of the user, under the different Campaigns..

I want to get the list of MyProjects by the userid, and then iterate (with the keys i got from MyProjects) over the campaigns -(key)-> projects -(key)-> profileId and compare them... (hope it was clear enough...)

HOW DO I DO THAT?

Ok, after some more research, i went a different way. it seems like i don't need "MyProjects".

var userId = "-Kxx_egu9h4GOrxqM1nB";
var campaignRef = this.db.app.database().ref('Campaign'); //root
var projectsRef = campaignRef.child('Projects');

projectsRef.orderByChild('profileId').equalTo(userId).once("value", (snap) => {
  console.log(snap.val());
});

but still i get NULL.. (tried "child_added" and .on in different combinations - nothing...)

Answer 1

After logging in, and pulling the Campaign object, you can try running the following code:

// user is an object from the userProfile. You can also just directly access the object and get what you need. Really, it's up to you. I'll assume that you also stored the user ID (uid) here too.
var user = {},
  campaigns = {},
  uid = {},
  myProjects = [];

function getProjects() {
  for (var i in campaigns) {
    for (var k in campaigns[i]) {
      // Make sure that the profileId of the project and the uid match, then push object into myProjects array
      campaigns[i][k].profileId === uid ? myProjects.push(campaigns[i][k]) : 'nada';
    }
  }
}

In the myProjects array will you find your projects.