如何获取 MongoDB 查询中所有文档的大小?
mongodbdatabasebig data analytics更新于 2026/1/12 16:37:17
要获取查询中所有文档的大小，您需要循环遍历文档。首先，我们创建一个包含文档的集合 −
> db.sizeOfAllDocumentsDemo.insertOne({"StudentFirstName":"John","StudentSubject":["MongoDB","Java"]});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cd3c0c1edc6604c74817cd7")
}
> db.sizeOfAllDocumentsDemo.insertOne({"StudentFirstName":"Larry","StudentSubject":["MySQL","PHP"],"StudentAge":21});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cd3c0d9edc6604c74817cd8")
}
> db.sizeOfAllDocumentsDemo.insertOne({"StudentFirstName":"Chris","StudentSubject":["SQL Server","C#"],"StudentAge":23,"StudentCountryName":"US"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cd3c0fbedc6604c74817cd9")
}
以下是使用 find() 方法显示集合中的所有文档的查询 −
> db.sizeOfAllDocumentsDemo.find().pretty();
这将产生以下输出 −
{
"_id" : ObjectId("5cd3c0c1edc6604c74817cd7"),
"StudentFirstName" : "John",
"StudentSubject" : [
"MongoDB",
"Java"
]
}
{
"_id" : ObjectId("5cd3c0d9edc6604c74817cd8"),
"StudentFirstName" : "Larry",
"StudentSubject" : [
"MySQL",
"PHP"
],
"StudentAge" : 21
}
{
"_id" : ObjectId("5cd3c0fbedc6604c74817cd9"),
"StudentFirstName" : "Chris",
"StudentSubject" : [
"SQL Server",
"C#"
],
"StudentAge" : 23,
"StudentCountryName" : "US"
}
以下查询用于获取查询中所有文档的大小 −
> var allDocument = db.sizeOfAllDocumentsDemo.find();
> var counter = 0;
> allDocument.forEach(
... function(myDocument) {
... counter = counter+Object.bsonsize(myDocument)
... }
... );
> print(counter);
这将产生以下输出 −
358
