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POupdating column based off of parent information
 

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    <p>I am a beginner at SQL Server and I have a question about how best to do this.</p> <p>I have a table that looks like this:</p> <p>ID&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Parent&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Level<br> 1&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;NULL&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0<br> 2&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1<br> 3&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1<br> 4&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2<br> 5&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2<br> 6&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2<br> 7&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2<br> 8&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;4<br> 9&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;4&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3<br> 10&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3<br> 11&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3<br></p> <p>As you can see, all the entries have a Parent and a Level and the database is organized in a tree structure. There are some entries where the Level is set incorrectly such as entry ID #8. The Parent of 8 is 5 and ID 5 has a level of 2 so the level of 8 should be 3 and not 4. There are many incorrect Level values in my table and I'm not sure how to fix this. So far I have this:</p> <p>UPDATE myTable<br> SET level=level-1<br> FROM myTable<br> WHERE ???;<br></p> <p>I am not sure how to fill in the WHERE part or whether this is the best way to do this. Any suggestions are gladly appreciated.</p>
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    1. COI'm afraid that any advice I would give you would be dangerous since I don't know exactly what it is that you're trying to accomplish. Perhaps if you gave some indication of what the table was supposed to look like?
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    2. COYou could use a cursor to handle the update, but it would be messy. The first thing to do would be to fix the portion that caused this problem initially.
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      1. USLeppyR64
 

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