CODEWITHSUNDEEP
phpmongodb
oniramarf
oniramarf

Reputation: 903

MongoDB: update several documents with one operation

I have to update lots of documents on MongoDB and I would like to do this in one operation with the server.

On a relational database such as MYSQL, I would do something like this:

$mysql = new MySQLi($host, $user, $pwd, $db, $port);
$q = "INSERT INTO table (idField, field) VALUES ";

foreach($elements as $el) {
  $q .= "({$el->id}, {$el->field}),";
}

$q = substr($q, 0, -1) . " ON DUPLICATE KEY UPDATE field = VALUES(field)";
$mysql->query($q);

Is there a possibility to do the same thing also in MongoDB? At the moment I have something like this:

$mongo = new MongoDB\Client("mongodb://{$host}:{$port}");
$col = $mongo->selectDatabase($db)->selectCollection($collectionName);

foreach($elements as $el) {
  $col->updateOne(array("id" => $el->id), array("field" => $el->field));
}

But this would cause a lot of connections to the database, causing a very slow process for billions of rows.

EDIT:

The following is an example of the starting data set:

{idField: 1, field: "A"}
{idField: 2, field: "B"}
{idField: 3, field: "C"}

Then I'd like to modify the field where idField is 1 to Alpha and a fieldAdded with Aleph, 2 to Beta and add Bet, 3 to Gamma and add Ghimel, obtaining the following resulting set:

{idField: 1, field: "Alpha", fieldAdded: "Aleph"}
{idField: 2, field: "Beta", fieldAdded: "Bet"}
{idField: 3, field: "Gamma", fieldAdded: "Ghimel"}

Is it possible to do so with just one request to the database?

Upvotes: 1

Views: 188

Answers (1)

chridam
chridam

Reputation: 103305

Use the bulkWrite method to do a bulk update as follows

$ops = array();      

foreach ($elements as $el) {  
    $update = [
        'updateOne' => [
            [ 'id' => $el->id ], 
            [ '$set' => [ 'field' => $el->field ] ]
        ]
    ];          
    array_push($ops, $update);                        
}

$result = $col->bulkWrite($ops);
echo $result->getModifiedCount();

Upvotes: 1

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