Add example table to sum_distinct section

Generated-By: mintlify-agent

Author: mintlify[bot]

references/metrics.mdx

@@ -896,7 +896,18 @@ The metric orders by the value being summed and takes the first occurrence for e
 
 **Example: Summing order shipping costs**
 
-Consider a model containing `order_id`, `order_shipping_cost`, and `order_line_item_id`. If you want to sum shipping costs for all orders, you need to deduplicate by `order_id` since each order has multiple line items but only one shipping cost:
+Consider a model containing `order_id`, `order_item_id`, and `order_shipping_amount`:
+
+| order_id | order_item_id | order_shipping_amount |
+|----------|---------------|-----------------------|
+| 1        | 1             | 10                    |
+| 1        | 2             | 10                    |
+| 2        | 3             | 20                    |
+| 2        | 4             | 20                    |
+| 2        | 5             | 20                    |
+| 2        | 6             | 30                    |
+
+If you want to sum shipping amounts for all orders, you need to deduplicate by `order_id`. When `order_id` is the distinct key, the first `order_shipping_amount` in ascending order will be taken for each order. In this example, order 1 contributes 10 and order 2 contributes 20 (the first value when ordered ascending), giving a total of 30:
 
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