MongoDB游标在Perl中进行哈希处理(MongoDB cursor to hash in Perl)

MongoDB游标在Perl中进行哈希处理(MongoDB cursor to hash in Perl)

所以，我正在从MongoDB中检索一些值。 我现在的find方法返回一个cursor ，它延迟加载查询结果。 我想将光标存储为哈希，但我可以找到任何方法。 当然，你可以迭代光标并自己填充，但我对自动化方式感兴趣。 例如，在Python中，您可以这样做： myList = list(col.find())将所有游标项目作为列表。

是否有可能在Perl中做类似的事情？

So, I'm retrieving some values from MongoDB. I now that find method returns a cursor, which lazy loads the query results. I want to have the cursor stored as a hash, but I can find any method. Of course, you can iterate over the cursor and fill the has by yourself, but I'm interested in a automated way. For example, in Python, you could do this: myList = list(col.find()) to get all the cursor items as a list.

Would it be possible doing something similar in Perl?

最满意答案

当你调用find ，它返回一个游标对象 ，它将迭代器方法委托给MongoDB :: QueryResult 。 当你做next件事时，它会懒洋洋地一次返回一个文档。 该文件已经是完整的数据集。 这可能是一个哈希引用（或者一个对象，我不知道）。

use Data::Dumper; while (my $object = $cursor->next) { print Dumper $object; }

如果你想同时使用所有这些方法，你可以获得一个包含all方法的列表，然后可以将它放入一个数组中并在方便时使用。 这不会按需加载。

my @objects = $cursor->all;

When you call find, it returns a cursor object, which delegates iterator methods to a MongoDB::QueryResult. When you do a next on that thing, it returns one document at a time lazily. That document already is the full set of data. This might be a hash reference already (or an object, I don't know).

use Data::Dumper; while (my $object = $cursor->next) { print Dumper $object; }

If you want all of them at once, you can get a list with the all method, which you can then put into an array and use at your convenience. This will not load on demand.

my @objects = $cursor->all;