Retrieving Latest Rows for Each Seller ID in Laravel Eloquent
This article addresses the challenge of retrieving the most recent row for each unique seller in a database table. We will explore a solution using the Laravel Eloquent ORM to achieve this goal.
The given table contains data for sales, including seller IDs, amounts, and creation timestamps. To obtain the latest row for a specific seller, the query can be written as:
<code class="php">$sales = Snapshot::where('seller_id', '=', 15) ->orderBy('created_at', 'DESC') ->first();</code>
To extend this functionality to retrieve the latest rows for all sellers, we employ a more advanced query. The following query utilizes a subquery to identify the latest row for each seller:
<code class="sql">select s.* from snapshot s left join snapshot s1 on s.seller_id = s1.seller_id and s.created_at < s1.created_at where s1.seller_id is null
To use this query in Laravel's query builder, the following code can be implemented:
<code class="php">DB::table('snapshot as s') ->select('s.*') ->leftJoin('snapshot as s1', function ($join) { $join->on('s.seller_id', '=', 's1.seller_id') ->whereRaw(DB::raw('s.created_at < s1.created_at')); }) ->whereNull('s1.seller_id') ->get();</code>
Through this solution, you can efficiently retrieve the latest row for each seller in the database table, providing convenient access to the most up-to-date data for your application.
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