Issues regarding MongoDB queries and import

Question

I'm trying to learn MongoDB, and I'm running into issues. First one, I'd like to for example search for every embedded document that has the field "vuosi" equal less than 2019. I tried the following:

db.yhtyeet.find( { "levyt": { vuosi: { $lt: 2019 } } } );

Here's how the Database .json file reads out:

{
  "nimi": "Koodaajaorkesteri",
  "levyt": [
    {
      "nimi": "Koodinvääntäjä",
      "vuosi": 2013,
      "genret": [1, 2],
      "kappaleet": [
        {
          "nimi": "Koodaa kuin mies",
          "sav": "Tommi",
          "san": "Tommi"
        },
        {
          "nimi": "Ikuinen silmukka",
          "sav": "Jakke",
          "san": "Jakke"
        },
        {
          "nimi": "Iisi ostaa verkosta",
          "sav": "Jakke",
          "san": "Niko"
        }
      ]
    },
    {
      "nimi": "Syntax Error",
      "vuosi": 2019,
      "genre": [1, 2],
      "kappaleet": [
        {
          "nimi": "Pistetään pistetään omenaa poskeen",
          "sav": "Jakke",
          "san": "Jakke"
        },
        {
          "nimi": "Testaajahumppa",
          "sav": "Niko",
          "san": "Jakke"
        }
      ]
    }
  ]
}

Another issue: I'm trying to import multiple .json files into MongoDB. Firstly, is it correct to separate them with a comma?

$ docker exec -i nosql_mongo_1 mongoimport -u root -ppassword --authenticationDatabase=Admin -d ikk -c < ikk.json, ikkkayttaja.json, ikkroolit.json, ikktagit.json

The issue I'm getting is ikk.json,: No such file or directory even though it does exist and I'm in the correct folder. Is there something wrong with the file itself regarding syntax? Here are its contents:

{
    nimi: "PingPong",
    luokka: "Peli",
    tagit: [2, 3],
    tekijat: [
        {
            nimi: "Keijo-Antero Kuronen",
            rooli: [1, 2]
        },
        {
            nimi: "Sanna Suomalainen",
            rooli: [3, 4]
        }
    ],
    katsottu: 100,
    ladattu: 21
}
{
    nimi: "Tiko-Karate",
    luokka: "Peli",
    tagit: [1, 3, 4],
    tekijat: [
        {
            nimi: "Raimo Ruuskanen",
            rooli: [1, 3]
        },
        {
            nimi: "Pentti Puustinen,
            rooli: [3, 4]
        }
    ],
    katsottu: 55,
    ladattu: 23
}
{
    nimi: "Naamakirja",
    luokka: "Hyotysovellus",
    tagit: [5, 6],
    tekijat: [
        {
            nimi: "Ilmari Immonen-Innanen",
            rooli: [1, 5]
        },
        {
            nimi: "Raija-Irmeli Rantanen",
            rooli: [1, 3, 4]
        }
    ],
    katsottu: 133,
    ladattu: 16
}

score 0 · Answer 1 · answered Feb 04 '20 at 11:06

To answer your first question, you can query the nested document by referencing the first field and the nested one with a dot notation "field.nestedField" (see documentation):

db.inventory.find( { "levyt.vuosi": { $lt: 2019 } } );

To answer your second question, you cannot import multiple collections with mongoimport (see documentation). You can do a workaround with script commands to call mongoimport in a loop. This question can help : Import more than 1 json file using mongoimport.

Issues regarding MongoDB queries and import

1 Answers1