CODEWITHSUNDEEP
mongodbcounterupsert
SCO
SCO

Reputation: 1932

How to add/update dynamic counters in Mongodb?

Here is my CSV file :

12;France;http://www.google.com
12;France;http://www.google.com

For each line, the $field[] structure I use to populate my Mongo object looks like the following :

array(18) {
  ["date_day"]=>  int(12)
  ["url"]=>  string(21) "http://www.google.com"
  ["country"]=>  string(6) "France"
}

For each of these two lines, I call the following :

$result = $coll->update ( array ( 'ts_day' => $field['date_day'] ,'url'=>$field['url']),array('$addToSet' => array ( "countries" => array ( 'name' =>$field['country'] )) ),array ('upsert' => true ));

$result = $coll->update ( array ( 'ts_day' => $field['date_day'] ,'url' => $field['url'] , 'countries.name' => $field['country'] ),array ( '$inc' => array( 'countries.$.views'=> 1) ) ,array ( 'upsert' => true));

I don't understand why I get an extra { "name" : "France" } object in the "countries" array, with no "views" counter, although the counter is properly incremented in countries.france.views (whose value is 2, which is correct) :

{ "_id" : ObjectId("4eeb0e6cd86450af72f775be"), "url" : "http://www.google.com", "countries" : [ { "name" : "France", "views": 2 }, { "name" : "France" } ], "ts_day" : 12 }

Any idea for this lonely { "name" : "France" } ? Mongo bug or misunderstanding of mine ?

Thank you !

Upvotes: 0

Views: 913

Answers (3)

SCO
SCO

Reputation: 1932

This does the trick :

$result = $coll->update ( array ( 'ts_year' => $field['date_year'] , 'ts_month' => $field['date_month'] , 'ts_day' => $field['date_day'] , 'asset' => $field['url'] ), array ( '$inc' => array( "countries.".$field['country'].".views" => 1) ) ,array ( 'upsert' => true));

Upvotes: 0

brandon10gen
brandon10gen

Reputation: 361

It sounds like you're getting too hung up on using the standard mongoimport/export tools to process your CSV files.

If you check out the source code, you'll notice that these two tools are rather simple client applications that utilize the MongoDB C++ driver. Were they written in Python or Ruby, they'd like only be 5-10 lines long.

Why don't you simply write a new script that reads in the CSV file and inserts the documents in exactly the way you'd like? Want to do aggregation? Do it in client code! Want total control over the schema? You're set!

In fact, this would be the best way forward -- mongoimport/export is provided for convenience not comprehensiveness. If your data ingestion process requires significantly updating a large number of documents once they've already been written to the database, you may even start to see issues with compaction and performance.

Upvotes: 1

DhruvPathak
DhruvPathak

Reputation: 43235

You need to use $inc operator. This will increment the target field, if it matches the criteria you specified.

http://www.mongodb.org/display/DOCS/Updating#Updating-%24inc

Upvotes: 0

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