从 SqlDataReader 填充数组(或数组列表)

Fill an array (or arraylist) from SqlDataReader(从 SqlDataReader 填充数组(或数组列表))

问题描述

有没有一种方法可以通过 SqlDataReader(或任何其他 C# ADO.NET 对象)填充数组，而无需遍历所有项目?我有一个返回单列的查询，我想将其放入字符串数组(或 ArrayList 或 List 等)中.

Is there a way to fill an array via a SqlDataReader (or any other C# ADO.NET object) without looping through all the items? I have a query that is returning a single column, and I want to put that into a string array (or ArrayList, or List, etc).

推荐答案

有可能.在 .NET 2.0+ 中，SqlDataReader 继承自 DbDataReader，后者实现了 IEnumerable(非泛型).这意味着您可以使用 LINQ:

It is possible. In .NET 2.0+, SqlDataReader inherits from DbDataReader, which implements IEnumerable (non-generic one). This means that you can use LINQ:

List<string> list = (from IDataRecord r in dataReader
                     select (string)r["FieldName"]
                    ).ToList();

也就是说，循环仍然存在，它只是隐藏在 Enumerable.Select 中，而不是在您的代码中显式显示.

That said, the loop is still there, it's just hidden in Enumerable.Select, rather than being explicit in your code.

这篇关于从 SqlDataReader 填充数组(或数组列表)的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！