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    <p>Following <code>CTE</code> returns your given output for your given inputs. You can use these results as a starting point for inserting the records into another table.</p> <p>The gist of it is </p> <ul> <li>Use a recursive <code>CTE</code>, starting with all rows where <code>rn=1</code>.</li> <li>In the recursive part, pick <code>Data1-3</code> from the recursive part if available, otherwise retain the exisiting value (<code>COALESCE</code>). The result of the <code>CTE</code> now is your final values + the initial values where <code>rn=1</code></li> <li>Add a <code>ROW_NUMBER</code> for each <code>userID</code> but <code>ORDER DESC</code> on the existing <code>rn</code>. This makes sure that the <em>latest</em> values get rownumber 1.</li> <li>Finally select all with rownumber 1 and add another rownumber as per your final results.</li> </ul> <p><strong>SQL Statement</strong></p> <pre><code>;WITH q AS ( SELECT rn , UserID , Data1 , Data2 , Data3 FROM Inherited WHERE rn = 1 UNION ALL SELECT i.rn , i.UserID , COALESCE(i.Data1, q.Data1) , COALESCE(i.Data2, q.Data2) , COALESCE(i.Data3, q.Data3) FROM q INNER JOIN Inherited i ON i.rn = q.rn+1 AND i.userID = q.userID ) SELECT rn = ROW_NUMBER() OVER (ORDER BY userID) , * FROM ( SELECT UserID , Data1 , Data2 , Data3 , rn = ROW_NUMBER() OVER (PARTITION BY UserID ORDER BY rn DESC) FROM q ) t WHERE rn = 1 </code></pre> <p><strong>Test Script</strong></p> <pre><code>;WITH Inherited (rowID, rn, userID, Data1, Data2, Data3) AS ( SELECT * FROM (VALUES (1, 1, 1, 'A', null, '123') , (2, 2, 1, 'B', '111', null) , (3, 1, 2, 'C', '222', '333') , (4, 2, 2, 'D', null, null) , (5, 3, 2, 'E', '111', null) , (6, 1, 3, 'F', '333', '222') ) a (b, c, d, e, f, g) ) , q AS ( SELECT rn , UserID , Data1 , Data2 , Data3 FROM Inherited WHERE rn = 1 UNION ALL SELECT i.rn , i.UserID , COALESCE(i.Data1, q.Data1) , COALESCE(i.Data2, q.Data2) , COALESCE(i.Data3, q.Data3) FROM q INNER JOIN Inherited i ON i.rn = q.rn+1 AND i.userID = q.userID ) SELECT rn = ROW_NUMBER() OVER (ORDER BY userID) , * FROM ( SELECT UserID , Data1 , Data2 , Data3 , rn = ROW_NUMBER() OVER (PARTITION BY UserID ORDER BY rn DESC) FROM q ) t WHERE rn = 1 </code></pre>
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    1. POCan a CTE be used to update in passes?
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    1. USLieven Keersmaekers
    1. USLieven Keersmaekers
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    1. COVery cool, and it works. I also think I understand it: On the first pass, you have the anchors (rn=1). Then q UNIONS with itself and JOINS itself on the NEXT record (rn+1). This allows it to coalesce the data. We keep going until rn+1 condition fails. This give us a set of sequentially coalesced rows, and we output the user table with the latest row. Do I have it? (I love this by the way!)
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      1. USuser991945
    2. CO@user991945 - You've explained it better than I could <g>.
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