title: Count product selled in a day for each type of product
body: <p>I have a problem in my query.
  Imagine I have 10 product (product1, product2, product3), and today (08/16/2021), I'm selling 15 &quot;product1, 2 product2 and 5 product3. I need to now every day how many product I sold, and be able to get all of them for each day.</p>
  <p>Tell me if my class are good enough, and what query or code can I use.</p>
  <pre><code>@Entity(tableName = &quot;stock_products&quot;)
  data class StockProducts (
  
      @PrimaryKey(autoGenerate = false)
      val id: String,
  
      @ColumnInfo(name = &quot;timestamp&quot;)
      val timestamp: String,
  
      @ColumnInfo(name = &quot;productName&quot;)
      val orderList: List&lt;ProductInfo&gt;
  )
  </code></pre>