[英]Mongodb find query optimization
I'm writing a migration script
to update some fields of a collection, say collection2
. 我正在编写一个migration script
来更新集合的某些字段,例如collection2
。 In our collections, we store Japanese dates with following format in each document: 在我们的集合中,我们在每个文档中存储以下格式的日语日期:
"date" : { "era" : 4, "year" : 25, "month" : 11, "day" : 25 }// i.e `25-11-2014`
Now I'm looking for an easy way to get all the documents of the collection with date > 1-10-2014
ie 现在,我正在寻找一种简单的方法来获取date > 1-10-2014
的馆藏的所有文档,即
date > { "era" : 4, "year" : 25, "month" : 10, "day" : 1 }
Code works well, but I'm feeling like it can be optimised but don't know how. 代码运行良好,但我感觉可以对其进行优化,但不知道如何做。
collection1
using forEach
and extracting its date 使用forEach
迭代collection1
并提取其日期 collection1.date > 1-10-2014
检查日期collection1.date > 1-10-2014
日期collection1.date > 1-10-2014
copy some document fields from collection2
and update them 从collection2
复制一些文档字段并更新它们
db.col1.find({ name: x123 }).forEach(function(doc){ if(hasValidDate(doc.date1)){ db.col2.find({col1_id:doc._id}).forEach(function(doc2){ var copyobj = {doc2.x1, doc2.x2, ...}; db.col2.update({col1_id:doc._id}, copyobj); }); } }); function hasValidDate(date){ return (date.era == 4 && date.year >= 26 && (date.month >= 10 && date.day >= 1))?true:false; }
You could try including the actual date filtering within your find()
query: 您可以尝试在find()
查询中包括实际的日期过滤:
db.col1.find(
{
"name": "x123",
"date.era": 4,
"date.year": { "$gte": 26 },
"date.month": { "$gte": 10 },
"date.day": { "$gte": 1 },
}
).forEach(function(doc){
var copyobj = { "$set": {"x1": "1", "x2": "3", ...} };
db.col2.update({_id: doc._id}, copyobj);
});
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