如何使用MongoDB在CSV中存储数组的输出

Question

sample json data file

{
  "Includes": {
    "Employees": {
      "14": {
        "name": "john",
        "age": 12,
        "activity": {
          "Count": 3502,
          "RatingValue": 5
        }
      },
      "17": {
        "name": "smith",
        "age": 23,
        "activity": {
          "Count": 232,
          "RatingValue": 5
        }
      }
    }
  }
}

js was written to retrieve the nested document and stored in array

var result = [];

db.details.find().forEach(function(doc) {
    var Employees = doc.Includes.Employees;
    if (Employees) {
        for (var key in Employees) {
            var Employee = Employees[key];
            var item = [];
            item.push(key);
            item.push(Employee.name);
            item.push(Employee.age);
            item.push(Employee.activity.Count);
            item.push(Employee.activity.RatingValue);
            result.push(item.join(","));
        }
    }
});

print(result);

How can we store the output of array in csv with 2 rows because the data contains 2 rows by using mongoexport. In csv output must be

14,john,12,3502,5

17,smith,23,232,5

Answer 1

var csv=""; //this is the output file
for(var i=0;i<result.length;i++){//loop through output
    csv+=result[i]+"\n"; //append the text and a newline
}
window.open('data:text/csv;' + (window.btoa?'base64,'+btoa(csv):csv)); //open in a new window, chrome will automatically download since it is a csv.

Answer 2

Change that final print(result); to the following:

print(result.join("\n"));

Then call your script and direct the output to a CSV file like so:

mongo --quiet "full-path-to-script.js" > "full-path-to-output.csv"

Note: The --quiet arg suppresses the standard Mongo header output (shell version and initial database).

I created a details collection, and added your JSON document to it, and then running the modified script resulted in the following CSV file content:

14,john,12,3502,5
17,smith,23,232,5

If you want a CSV header row as well, see my nearly identical answer to your nearly identical question here: https://stackoverflow.com/a/26310323/3212415