UNNEST for Array Expansion

Basic UNNEST Filtering Unnested Data This filters the unnested items to include only those containing "premium". The result shows only matching items with their order IDs. Aggregating Unnested Arrays After unnesting, standard aggregation functions work on the expanded rows. This counts total item occurrences and unique items across all orders. UNNEST vs Lambda Functions After unnesting, you can group by the original row identifier to recollect elements, or apply aggregations across all elements from all rows together.