如何创建，创建最多100个对象组一个LINQ表达式 [英] How do I create a Linq expression that creates groups of max 100 objects

问题描述

我有一个LINQ表达式从Azure的表存储组客户的分区。

I have a LINQ expression that groups customers from an Azure Table Storage by partition.

由于Azure的只支持100的实体在同一时间，最大批处理操作（和实体在批量多有相同PartitionKey），我需要每个小组包含最多100元。

Because Azure only supports batch operations with max 100 entities at a time (and entities in a batch much have the same PartitionKey), I need each group to contain a maximum 100 entities.

//How to complete this LINQ expression
var groups = customers.GroupBy(c => c.PartitionKey)....;

//Do some Azure table storage magic in parallel
Parallel.ForEach(groups , customersInGroup => {...});

我如何完成我的LINQ表达式，所以每个组包含100最大客户？这是...如果客户收集如。拥有142客户拥有相同的PartitionKey，我想创建两个组...一组，100个客户，一个有42客户。

How do I complete my LINQ expression, so each group contains max 100 customers? That is... if the customers collection eg. has 142 customers with the same PartitionKey, i want to create two groups... one groups with 100 customers and one with 42 customers.

推荐答案

有没有什么是在正常的LINQ直接做到这一点，但 MoreLINQ 拥有的 批量 方法您可能会发现有用的：

There's nothing within "normal" LINQ to do this directly, but MoreLINQ has a Batch method which you may find useful:

public static IEnumerable<TResult> Batch<TSource, TResult>
    (this IEnumerable<TSource> source, int size,
     Func<IEnumerable<TSource>, TResult> resultSelector)

public static IEnumerable<IEnumerable<TSource>> Batch<TSource>
    (this IEnumerable<TSource> source, int size)

请注意，在你的情况倒是可能想是这样的：

Note that in your case you'd probably want something like:

var groups = customers.GroupBy(c => c.PartitionKey).Batch(100, p => p.ToList());

使返回的结果立即兑现。

so that the returned results are materialized immediately.

当然，这是假设你使用LINQ到对象 - 如果你想通过其他LINQ提供程序分区，我不知道你会如何去了解它。

Of course, this is assuming you're using LINQ to Objects - if you're trying to partition via another LINQ provider, I'm not sure how you'd go about it.

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