How to change delimiter from comma to # in a csv using MongoDB - mongodb

Question

Can the delimiter be changed from comma to # while exporting records to csv file.
In the below example
mongoexport -d mydb -c coll --csv --fields "ProductId,ModerationStatus,Rating,TotalCommentCount" --out results.csv

Answer 1

Currently, mongoexport does not have this feature.
However, you can develop a simple JavaScript for doing this. So you have the control over the format of csv and field data types.
export.js
conn = new Mongo();
db = conn.getDB("myDB");
var cur = db.myCollection.find();
var obj;
while(cur.hasNext()){
obj = cur.next();
print("\""+obj._id+"\";\""+obj.field_1+"\";\""+obj.field_2+"\"");
}
Call this script from your OS shell:
mongo --quiet export.js > file_name.csv
--quiet: disables Mongo default option to print "version", "connecting to", etc, therefore the output of the script will be just things printed explicitly using print()

Answer 2

not a very clean solution but you can build a your own version of mongoexport adding inside the code "Comma" statement
https://github.com/mongodb/mongo-tools/blob/master/mongoexport/csv.go
https://golang.org/pkg/encoding/csv/#Writer
// WriteHeader writes a comma-delimited list of fields as the output header row.
func (csvExporter *CSVExportOutput) WriteHeader() error {
if !csvExporter.NoHeaderLine {
//here the trick
csvExporter.csvWriter.Comma = '|'
//
csvExporter.csvWriter.Write(csvExporter.Fields)
return csvExporter.csvWriter.Error()
}
return nil
}