db.test.find();
{
_id: ObjectId('55e99a2190df7a911d6ed1f1'),
list: [
{
"aa": 10,
"data": "test"
},
{
"aa": 1,
"data": "test"
}
]
}
db.test.find({_id: ObjectId('55e99a2190df7a911d6ed1f1'), list: {'$elemMatch': {'aa': 1}}})
预期结果:
{_id: ObjectId('55e99a2190df7a911d6ed1f1'),
list: {
"aa": 1,
"data": "test"
}
PHPz2017-04-27 09:04:24
> db.customer.find().pretty()
{
"_id" : ObjectId("559bb1d1d39f0dcac2658f8e"),
"cust_id" : "abc123",
"ord_date" : ISODate("2012-10-03T16:00:00Z"),
"status" : "A",
"price" : 25,
"items" : [
{
"sku" : "mmm",
"qty" : 5,
"price" : 2.5
},
{
"sku" : "nnn",
"qty" : 5,
"price" : 2.5
}
]
}
{
"_id" : ObjectId("559bb1ead39f0dcac2658f8f"),
"cust_id" : "abc123",
"ord_date" : ISODate("2012-10-03T16:00:00Z"),
"status" : "B",
"price" : 30,
"items" : [
{
"sku" : "mmm",
"qty" : 6,
"price" : 3.5
},
{
"sku" : "nnn",
"qty" : 6,
"price" : 3.5
}
]
}
{
"_id" : ObjectId("559bb200d39f0dcac2658f90"),
"cust_id" : "abc123",
"ord_date" : ISODate("2012-10-03T16:00:00Z"),
"status" : "C",
"price" : 35,
"items" : [
{
"sku" : "mmm",
"qty" : 7,
"price" : 4.5
},
{
"sku" : "nnn",
"qty" : 7,
"price" : 4.5
}
]
}
> db.customer.find({"items.qty":6},{"items.$":1}).pretty() //只返回和查询条件匹配的那一个元素
{
"_id" : ObjectId("559bb1ead39f0dcac2658f8f"),
"items" : [
{
"sku" : "mmm",
"qty" : 6,
"price" : 3.5
}
]
}
查询匹配的内嵌文档,你也可以直接查询,如:
> db.customer.find({"items.qty":6}).pretty()
{
"_id" : ObjectId("559bb1ead39f0dcac2658f8f"),
"cust_id" : "abc123",
"ord_date" : ISODate("2012-10-03T16:00:00Z"),
"status" : "B",
"price" : 30,
"items" : [
{
"sku" : "mmm",
"qty" : 6,
"price" : 3.5
},
{
"sku" : "nnn",
"qty" : 6,
"price" : 3.5
}
]
}
对应你上面的查询实现:
> db.customer.find({"_id":ObjectId("559bb1ead39f0dcac2658f8f"),items: {'$elemMatch': {'sku': "mmm"}}},{"items.$":1}).pretty()
{
"_id" : ObjectId("559bb1ead39f0dcac2658f8f"),
"items" : [
{
"sku" : "mmm",
"qty" : 6,
"price" : 3.5
}
]
}
db.test.find({_id: ObjectId('55e99a2190df7a911d6ed1f1'), list: {'$elemMatch': {'aa': 1}}},{"list.$":1}).pretty()
PHPz2017-04-27 09:04:24
首先 你用mongodb 你得明白 monggodb是nosql
然后 mongo的collection中存储的是document
最后 你要知道 find 返回的值一定是一个document的集合 也就是个array
所以你说的 基本上无法实现