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DynamoDB Group Count By

We are trying to search dynamodb and we need to get the number of objects in a group, how can this be done?

I tried this, but when adding the second number it doesn't work:

$search = array(
    'TableName'     => 'dev_adsite_rating',
    'Select'        => 'COUNT',
    'KeyConditions' => array(
        'ad_id' => array(
            'ComparisonOperator' => 'EQ',
            'AttributeValueList' => array(
                array('N' => 1039722, 'N' => 1480)
            )
        )
    )
);
$response = $client->query($search);

The sql version will look something like this:

select ad_id, count(*) 
from dev_adsite_rating
where ad_id in(1039722, 1480)
group by ad_id;

So, is there a way to achieve this? I can't find anything on it.

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1 answer


Trying to execute such a query in DynamoDB is a little more difficult than it is in the SQL world. To accomplish something like this, you need to consider several things



  • EQ ONLY Hash Key . To fulfill such a request, you need to make two requests (for example, ad_id EQ 1039722 / ad_id EQ 1480).
  • Paginate via query . Since dynamodb returns your result in many increments, you will need to paginate your results. More information ...
  • Start "Count" . You can take the "Count" property from the response and add it to the current summary as you are paginating the results of both queries. API requests
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