Entity Framework Plus-foreach循环中的FutureValue() [英] Entity Framework Plus - FutureValue() in a foreach loop

问题描述

最近我开始在我们的项目中成功使用 EF + ，但是有时候我遇到了一个问题有一组实体，我需要为其运行单独的查询.

Recently I started using EF+ on our project with great success however sometimes I run into an issue that I have a set of entities for which I need to run a separate query.

因此，如果我有20个客户，则需要分别运行20个查询.我想知道是否有办法在foreach循环中以某种方式避免使用EF + FutureValue().

So if I have a set of 20 customers I need to run 20 queries separately. I wonder if there is way how to avoid this using EF+ FutureValue() somehow in a foreach loop.

请参阅以下示例代码:

foreach (var customer in customers)
                {
                    customer.SomeValue = ctx.SomeDatabaseTable.Where(myCondition).FutureValue();
                    // this would run 20 times ... any way how to run all of the 20 queries at once?
                }

推荐答案

您需要首先生成所有"QueryFuture"查询，然后才能使用它们.

You need first to generate all "QueryFuture" queries then you can use them.

所以两个循环应该可以使它工作.

So two loop should make it works.

var futureQueries = new List<BaseQueryFuture>();

// create all query futures
for(int i = 0; i < customers.Length; i++)
{
    futureQueries.Add(ctx.SomeDatabaseTable.Where(myCondition).FutureValue());
}

// assign result (the first solved will make the call to the DB)
for(int i = 0; i < customers.Length; i++)
{
     customer.SomeValue = ((QueryFutureValue<SomeValueType>)futureQueries[i]).Value;
}

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