DynamicQueryable 如何支持数组运算符？

发布于 2024-10-18 00:30:07 字数 842 浏览 3 评论 0原文

我一直在使用 Scott Guthrie 的博客文章。

该文档有一个支持的运算符表。主要运算符之一如下：

x[…] 数组或索引器访问。不支持多维数组。

但是，我不知道如何使用它。

我没想到以下任何一个都会起作用，事实上它们也不起作用。

var ctx = new MyDbContext();
var parameters = new Object[] { new int[] { 1, 2, 3 } };

var qry = ctx.Set<User>().Where<User>("it.Id in @0", parameters);
var qry = ctx.Set<User>().Where<User>("it.Id.In(@0)", parameters);
var qry = ctx.Set<User>().Where<User>("it.Id = @0", parameters);
var qry = ctx.Set<User>().Where<User>("@0.Contains(it.Id)", parameters);

它基本上是一个 In 查询，但我不知道如何表达它。

原文

I have been using the DynamicQueryable Linq extensions featured in Scott Guthrie's blog post.

The documentation has a table of supported operators. One of the primary operators is the following:

x[…]
Array or indexer access. Multi-dimensional arrays are not supported.

However, I cannot figure out how it can be used.

I didn't expect any of the following to work and in fact they don't.

var ctx = new MyDbContext();
var parameters = new Object[] { new int[] { 1, 2, 3 } };

var qry = ctx.Set<User>().Where<User>("it.Id in @0", parameters);
var qry = ctx.Set<User>().Where<User>("it.Id.In(@0)", parameters);
var qry = ctx.Set<User>().Where<User>("it.Id = @0", parameters);
var qry = ctx.Set<User>().Where<User>("@0.Contains(it.Id)", parameters);

It is basically an In query, but I am not sure how to express it.

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无所的.畏惧 2024-10-25 00:30:07

这或许是一个误会。意思是可以查询特定索引位置处的集合元素。例如：

public class Order
{
    public List<OrderDetail> OrderDetails { get; set; }
}

public class OrderDetail
{
    public string Description { get; set; }
}

然后您可以通过以下方式查询第三个 OrderDetail 中具有详细描述“Bicycle”的所有订单：

string parameter = "Bicycle";
var qry = ctx.Set<Order>().Where<Order>("it.OrderDetails[2].Description == @0",
    parameter);

我认为出于您的目的，您需要建立一个“OR”链 "it.Id == 1 或it.Id == 2 或 it.Id == 3"（或在循环中动态构建此查询字符串），Where 方法中不带参数。

This is perhaps a misunderstanding. Meant is that it is possible to query for collection elements at a specific index position. For example:

public class Order
{
    public List<OrderDetail> OrderDetails { get; set; }
}

public class OrderDetail
{
    public string Description { get; set; }
}

Then you can query for all orders which have the Detail description "Bicycle" in the third OrderDetail by:

string parameter = "Bicycle";
var qry = ctx.Set<Order>().Where<Order>("it.OrderDetails[2].Description == @0",
    parameter);

I think for your purpose you need to build up an "OR" chain "it.Id == 1 or it.Id == 2 or it.Id == 3" (or build this query string dynamically in a loop) without parameters in the Where method.

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