使用 Presto 查询 MongoDB 嵌入式/嵌套文档数组

Question

假设我有以下文件：

db.inventory.insertMany( [
   { item: "journal", instock: [ { warehouse: "A", qty: 5 }, { warehouse: "C", qty: 15 } ] },
   { item: "notebook", instock: [ { warehouse: "C", qty: 5 } ] },
   { item: "paper", instock: [ { warehouse: "A", qty: 60 }, { warehouse: "B", qty: 15 } ] },
   { item: "planner", instock: [ { warehouse: "A", qty: 40 }, { warehouse: "B", qty: 5 } ] },
   { item: "postcard", instock: [ { warehouse: "B", qty: 15 }, { warehouse: "C", qty: 35 } ] }
]);

我想根据仓库和数量查询库存单据。在 mongo shell 中我会这样做：

db.inventory.find( { "instock": { $elemMatch: { qty: 5, warehouse: "A" } } } )

我将如何在 Presto 中执行此操作？

Answer 1

instock 将映射到 array(row(warehouse varchar, qty double)) 类型，$elemMatch 等于 Trino（以前称为 Presto SQL）中的 any_match 数组函数。

select * from inventory where any_match(instock, x -> x.qty = 5 and x.warehouse = 'A');
  item   |                      instock
---------+---------------------------------------------------
 journal | [{warehouse=A, qty=5.0}, {warehouse=C, qty=15.0}]