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POIssue with Group By in LinQ Query
 

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  1. POIssue with Group By in LinQ Query
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    <p>I want to make a LinQ query against an array with and return multiple columns. I can't seem to get it working correctly, and I've tried various things.</p> <p>First off, the array contains a type and a version from a table such as:</p> <pre><code>TypeID-------VersionID-------Text 1 1 "Version 1.1" 2 1 "Version 2.1" 3 1 "Version 3.1" 3 2 "Version 3.2" </code></pre> <p>This is a SQL table, and I could easily get the latest version with this query:</p> <pre><code>SELECT V.* FROM Table V WHERE V.VersionID IN (SELECT MAX(VersionID) GROUP BY TypeID) </code></pre> <p>However, I want to do this in LinQ and it's killing me. I can't figure it out. I want all the values. Therefore:</p> <pre><code>public MyStruct { public int TypeID, public int VersionID, public string Text } MyStruct[] array = new MyStruct[4]; array[0].TypeID = 1; array[0].VersionID = 1; array[0].Text = "Version 1.1"; array[1].TypeID = 2; array[1].VersionID = 1; array[1].Text = "Version 2.1"; array[2].TypeID = 3; array[2].VersionID = 1; array[2].Text = "Version 3.1"; array[3].TypeID = 3; array[3].VersionID = 2; array[3].Text = "Version 3.2"; </code></pre> <p>Now, I want a resultant array that only has three elements containing Version 1.1, Version 2.1, and Version 3.2. Since Version 3.1 is an "older version", I want to ignore it.</p> <p>My LinQ is like this:</p> <pre><code>var myArrayQuery = from arr in array group arr by arr.TypeID into arrGroup select new { TypeID = arrGroup.Key, VersionID = (int)arrGroup.Max(mx=&gt;mx.VersionID) // -- GET THE TEXT HERE --- }; </code></pre> <p>I can't figure out how to get the text!</p> <p>I have tried:</p> <pre><code>var myArrayQuery = from arr in array group arr by new{ arr.TypeID, arr.VersionID, arr.Text} into arrGroup select new { TypeID = arrGroup.TypeID, VersionID = (int)arrGroup.Max(mx=&gt;mx.VersionID), Text = arrGroup.Text }; </code></pre> <p>But then, it returns <em>all four</em> of my array elements. Therefore, no good. I don't get the MAX like I want.</p> <p>Please help!</p> <p>Thanks.</p>
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      1. POIssue with Group By in LinQ Query
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    1. This table or related slice is empty.
 

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