[英]Put Javascript Array Values into Mongodb Collection Values
I have a Javascript Array filled with mean Values and I want to insert them into a collection with a field named "mean". 我有一个填充了均值的Javascript数组,我想将它们插入到一个名为“mean”的字段的集合中。 The Field "mean" already exists and has already values in them and now I want to update them with the values of the Array.
字段“mean”已经存在并且已经存在值,现在我想用Array的值更新它们。 To be more specific: I want the first Value of the Array to be in the first Document under the field "mean" and so on.
更具体一点:我希望数组的第一个值位于“mean”字段下的第一个Document中,依此类推。 I have 98 Documents and the Array has also a length of 98.
我有98个文件,数组的长度也是98。
The Collection looks like this with the name "cmean": 该集合的名称如此“cmean”:
{
"_id" : "000",
"mean" : 33.825645389680915
}
{
"_id" : "001",
"mean" : 5.046005719077798
}
and the Array: 和数组:
[
33.89923155012405,
5.063347068609219
]
You can use the forEach
method on the array to iterate it and update the collection. 您可以在数组上使用
forEach
方法来迭代它并更新集合。 Use the index to get the _id
to be used in the update query, something like the following: 使用索引获取要在更新查询中使用的
_id
,如下所示:
meansArray.forEach(function(mean, idx) {
var id = db.cmean.find({}).skip(idx).limit(1).toArray()[0]["_id"];
db.cmean.updateOne(
{ "_id": id },
{ "$set": { "mean": mean } },
{ "upsert": true }
);
});
For large collections, you can streamline your db performance using bulkWrite
as follows: 对于大型集合,您可以使用
bulkWrite
简化数据库性能,如下所示:
var ops = [];
meansArray.forEach(function(mean, idx) {
var id = db.cmean.find({}).skip(idx).limit(1).toArray()[0]["_id"];
ops.push({
"updateOne": {
"filter": { "_id": id },
"update": { "$set": { "mean": mean } },
"upsert": true
}
});
if (ops.length === 1000 ) {
db.cmean.bulkWrite(ops);
ops = [];
}
})
if (ops.length > 0)
db.cmean.bulkWrite(ops);
update({"_id": id}, $set: {"mean": myArray}, function(res, err) { ... });
如果您使用的是mongoose,则还必须将数据模型从字符串更改为数组。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.