【发布时间】:2011-05-25 14:24:14
【问题描述】:
我很困惑,以下情况的最佳格式是什么:
Name: Pretty nice hot dog
Stock: 10
Weight: 0.1 grams
Price: 2 dollars
Name: An ordinary dumbbell
Stock: 5
Weight: 4 kilograms
Price: 667.98 yens
这个:
db.item.save ({"_id" : 1, "name" : "Pretty nice hot dog", "stock" : 10, "weight" : {"value" : 0.1, "unit" : "gram"}, "price" : {"value" : 2, "unit" : "dollar"}})
db.item.save ({"_id" : 2, "name" : "An ordinary dumbbell", "stock" : 5, "weight" : {"value" : 4, "unit" : "kilogram"}, "price" : {"value" : 667.98, "unit" : "yen"}})
或者这个:
db.unit.save ({"_id" : 1, "name" : "dollar"})
db.unit.save ({"_id" : 2, "name" : "yen"})
db.unit.save ({"_id" : 4, "name" : "gram"})
db.unit.save ({"_id" : 5, "name" : "kilogram"})
db.item.save ({"_id" : 1, "name" : "Pretty nice hot dog", "stock" : 10, "weight" : {"value" : 0.1, "unit" : [new DBRef ("unit", 4)]}, "price" : [new DBRef ("unit", 1)]})
db.item.save ({"_id" : 2, "name" : "An ordinary dumbbell", "stock" : 5, "weight" : {"value" : 4, "unit" : [new DBRef ("unit", 5)]}, "price" : [new DBRef ("unit", 2)]})
“unit”字段的值是不可变的,不知道该不该放在单独的集合中。
谢谢
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