英文:
MongoDB aggregation with $match and $group, $sum
问题
我正在尝试查询内部类的总和。我根据我在互联网上找到的内容将它组合在一起，但目前我得到的是一个空响应。我不太确定出了什么问题，因为我试图将不同部分组合在一起。
我不能创建任何自定义类，只能使用@Aggregation方法。
@Aggregation("{ $match: { 'object': $object, $and: [{'end': {$ne: null}}] } }, { '$group': { 'object': $object, 'object__price': { $sum: $object.price } } }")
Integer sumPrices(@Param("$object") Object object);
(代码中参数的名称是随机的。)
我正在尝试查询与对象名称匹配且生产值 ('end') 不为null的所有项目。然后，我想获取该类型的所有对象的总和并返回总和值。价格值是一个内部类。
英文:
I'm trying to query the sum of an inner class. I put it together with what I've found on the internet but I am getting an empty response at the moment. Not quite sure what is wrong with it, since it's different parts that I've tried to put together.
I cannot create any custom classes and I can only use the @Aggregation method.
@Aggregation(" { $match: { 'object': $object, $and: [{'end': {$ne: null}}] } }, { '$group' : { 'object' : $object, 'object__price': { $sum: $object.price }}}")
Integer sumPrices(@Param("$object") Object object);
(The names for the parameters are random in the code.)
I am trying to query for all items that match the object name and whose production value ('end') is not null. I then want to get the sum of all the objects of that types and return the sum value. Price value is an inner class.
答案1
得分: 0
尝试
@Aggregation(" { $match: { 'object': $object, $and: [{'end': {$ne: null}}] } }, { '$group' : { 'object' : $object, 'object__price': { $sum: "$price" }, count: {$sum: 1}}}")
" $sum: "$price" " 会给出该对象类型中每个文档的价格键的总和，count 会给出这些文档的总数
英文:
Try
@Aggregation(" { $match: { 'object': $object, $and: [{'end': {$ne: null}}] } }, { '$group' : { 'object' : $object, 'object__price': { $sum: "$price" }, count: {$sum: 1}}}")
" $sum: "$price" " would give the sum of key price of each document that falls in that object type, and count would give the total count of such documents
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