如果我理解得正确,这是一个存储在您的
Operation
集合中的示例文档:
{
clientRef: "john-001",
phone: "12345678",
other: "etc.",
savedOrder: {
"someMetadataAboutOrder": "...",
"lines" : [
{ qty: 1, itemRef: "XYZ001", unitPriceInCts: 1050, desc: "USB Pen Drive 8G" },
{ qty: 1, itemRef: "ABC002", unitPriceInCts: 19995, desc: "Entry level motherboard" },
]
}
},
{
clientRef: "paul-002",
phone: null,
other: "etc.",
savedOrder: {
"someMetadataAboutOrder": "...",
"lines" : [
{ qty: 3, itemRef: "XYZ001", unitPriceInCts: 950, desc: "USB Pen Drive 8G" },
]
}
},
考虑到这一点,要查找所有引用项目为
XYZ001
的操作,你只需查询:
> db.operations.find({"savedOrder.lines.itemRef":"XYZ001"})
这将返回整个文档。如果您只对客户端引用(以及操作 _id)感兴趣,您可以在
find
的额外参数中
使用投影:
> db.operations.find({"savedOrder.lines.itemRef":"XYZ001"}, {"clientRef": 1})
{ "_id" : ObjectId("556f07b5d5f2fb3f94b8c179"), "clientRef" : "john-001" }
{ "_id" : ObjectId("556f07b5d5f2fb3f94b8c17a"), "clientRef" : "paul-002" }
如果您需要执行多文档(包括多嵌套文档)操作,您应该查看
聚合框架:
例如,计算订单的总数:
> db.operations.aggregate([
{$match: { "_id" : ObjectId("556f07b5d5f2fb3f94b8c179") }},
{$unwind: "$savedOrder.lines" },
{$group: { _id: "$_id",
total: {$sum: {$multiply: ["$savedOrder.lines.qty",
"$savedOrder.lines.unitPriceInCts"]}}
}}
])
{ "_id" : ObjectId("556f07b5d5f2fb3f94b8c179"), "total" : 21045 }