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POWhat is the eqivalent to a SQL "in" clause here?
 

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  1. POWhat is the eqivalent to a SQL "in" clause here?
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    <p>I'm new to LINQ and I've been at this for hours now. I have a List&lt;> of objects where one of the objects properties is a List of selected categories. I also have, outside of the objects, a List representing a subset of categories and I want to return all objects which contain at least one category that is also in the subset as illustrated in the following pseudo code (not my actual code)</p> <pre><code>List&lt;string&gt; subset = cat, dog, mouse List&lt;myclass&gt; myclasses = {name:alphie, category:[cat,elephant]},{name:sally, category:[fish]}, {name:bob, category:[dog, mouse]} </code></pre> <p>In the above example I need to return alphie and bob since they both have at least one category that's in my subset. </p> <p>The only solution so far is to get a list of both and then use expensive foreach loops to go through and compare. I'm sure LINQ must provide a more efficient way to achieve the same?</p> <p>More details (I think my pseudo code is not detailed enough)</p> <pre><code>public class RadioProgram { ... private List&lt;string&gt; _category = new List&lt;string&gt;(); public List&lt;string&gt; Category { get { return _category; } set { _category = value; } } ... } public class Category { ... private string _categoryName = ""; private List&lt;Category&gt; _subCategories = new List&lt;Category&gt;(); public string CategoryName { get { return _categoryName; } set { _categoryName = value; } } public List&lt;Category&gt; SubCategories { get { return _subCategories; } set { _subCategories = value; } } ... } </code></pre> <p>I have a method, GetCategories(string parentCategory), that returns all child categoryNames as List. Each radioProgram.Category (yes, name needs to be refactored to plural) is itself a List and may contain zero, one or more categoryNames. I'm getting my master list of radioPrograms and I want to return a subset that contain where each one contains at least one categoryName that matches the set from GetCategories.</p> <p>I'm trying to avoid changing the architecture of the application (which is a potential solution) as it means a lot of refactoring of existing functionality AND I think this happens to be a good exercise for tackling and understanding LINQ.</p>
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