https://docs.mongodb.com/manual/reference/operator/aggregation/gte/
,你可以在上面蒙戈DB文档中看到,$ GTE返回哪个是假的太多数据。
例JSON数据:
{ "_id" : 1, "item" : "abc1", description: "product 1", qty: 300 }
{ "_id" : 2, "item" : "abc2", description: "product 2", qty: 200 }
{ "_id" : 3, "item" : "xyz1", description: "product 3", qty: 250 }
{ "_id" : 4, "item" : "VWZ1", description: "product 4", qty: 300 }
{ "_id" : 5, "item" : "VWZ2", description: "product 5", qty: 180 }
查询用于获取数据,其中数量大于250:
db.inventory.aggregate(
[
{
$project:
{
item: 1,
qty: 1,
qtyGte250: { $gte: [ "$qty", 250 ] },
_id: 0
}
}
]
)
输出:
{ "item" : "abc1", "qty" : 300, "qtyGte250" : true }
{ "item" : "abc2", "qty" : 200, "qtyGte250" : false }
{ "item" : "xyz1", "qty" : 250, "qtyGte250" : true }
{ "item" : "VWZ1", "qty" : 300, "qtyGte250" : true }
{ "item" : "VWZ2", "qty" : 180, "qtyGte250" : false }
问题: 那么我想要数据> qty> 250,但mongo db显示所有数据,因此当记录数量如此之高时,网站变得如此缓慢。
我在使用mongoid的rails上使用ruby,并且我有一些查询需要使用group by子句,所以我必须进行聚合,但这是返回所有数据。 我原来的查询:完美
data = SomeModel.collection.aggregate([
{"$project" => {
"dayOfMonth" => {"$dayOfMonth" => "$created_time"},
"month" => {"$month" => "$created_time"},
"year" => {"$year" => "$created_time"},
"date_check_gte" => {"$gte" => ["$created_time",start_time]},
"date_check_lte" => {"$lte" => ["$created_time",end_time]},
}},
{"$group" => {
"_id" => { "dayOfMonth" => "$dayOfMonth", "month" => "$month", "year" => "$year"},
"Total" => {"$sum" => 1},
"check_one" => {"$first" => "$date_check_gte"},
"check_two" => {"$first" => "$date_check_lte"}
}},
{"$sort" => {
"Total" => 1
}}
])
组,但是尽管采用GTE和LTE的返回的所有数据。 是否有任何可以完成的工作,以避免虚假数据出现?