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    <p>One solution would be to write your view to use a complex key, such as:</p> <pre><code>function (doc) { emit([doc.user, doc.count], doc.item); } </code></pre> <p>If you add <code>descending=true</code> to your query string, that would give you a view result like:</p> <pre><code>{"total_rows":4,"offset":0,"rows":[ {"id":"53f359b7cd360da296dd9aab3d0029bd","key":["john",15],"value":"D"}, {"id":"53f359b7cd360da296dd9aab3d001a0e","key":["bob",30],"value":"B"}, {"id":"53f359b7cd360da296dd9aab3d000fec","key":["bob",20],"value":"A"}, {"id":"53f359b7cd360da296dd9aab3d002668","key":["bob",10],"value":"C"} ]} </code></pre> <p>It's sorted already by user, then count. (with the item type as the value)</p> <p>Then you can use a <a href="http://guide.couchdb.org/editions/1/en/transforming.html" rel="nofollow"><code>_list</code> function</a> to do the rest. The code below basically loops through the view, and returns the top 2 results for each user. If you specify <code>user=bob</code> in the query string, you'll only get the results for <code>bob</code>.</p> <pre><code>function (head, req) { // specify that we're sending JSON as our response provides('json', function () { var results = [], result, user, count, row; while (row = getRow()) { // if the user doesn't match the last iteration, reset our counter if (user != row.key[0]) { user = row.key[0]; count = 0; } // we only need the top 2 if (count++ &gt;= 2) { continue; } // start building a result object result = { item: row.value, count: row.key[1] }; // if we provide user=? if (req.query.user) { // check to see if it matches the current user if (req.query.user === user) { // if so, add it to the results results.push(result); } // by default, we'll return the top 2 for every user } else { // add the user key to the result object result.user = row.key[0]; // and add it to the result set results.push(result); } } // send outside the loop, since it needs to be sent as valid JSON send(JSON.stringify(results)); }); } </code></pre>
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    1. CO+1 great answer. You might want to emphasize that the `_list` function is *optional*, it only adds convenience/consistency for the client however there is no *fundamental* change vs. the direct view query. That could help show that the answer is quite simple! Then there is a bonus exercise to make it perfect.
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