Cosmos DB SQL provides support for aggregations in the SELECT clause. For example, the following query uses the SUM aggregate function to sum all the values in the expression and calculate the total number of levels in the filtered games. The query uses the ARRAY_LENGTH built-in function to calculate the length of the levels array for each game and use it as an argument for the SUM aggregate function. The code file for the sample is included in the learning_cosmos_db_03_01 folder in the sql_queries/videogame_1_17.sql file:
SELECT SUM(ARRAY_LENGTH(v.levels)) FROM Videogames v
The following lines show the results of the query. Notice that the element of the array includes a key named $1:
[
{
"$1": 6
}
]
