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    <p>The functionality you're after is called "pivot"--it's converting row data into columnar data. The opposite is called "unpivot". There is PIVOT/UNPIVOT syntax, but it isn't available until Oracle 11g.</p> <p>On Oracle 9i+, <a href="http://techonthenet.com/oracle/functions/case.php" rel="nofollow">CASE statements</a> are used while prior to that you need to use <a href="http://techonthenet.com/oracle/functions/decode.php" rel="nofollow">DECODE</a> to construct the logic so the values come out in columns. Here's an example for addressing if the limit to LEVEL is five on Oracle 9i+:</p> <pre><code> SELECT MAX(CASE WHEN LEVEL = 1 THEN LEVEL END) AS one, MAX(CASE WHEN LEVEL = 2 THEN LEVEL END) AS two, MAX(CASE WHEN LEVEL = 3 THEN LEVEL END) AS three, MAX(CASE WHEN LEVEL = 4 THEN LEVEL END) AS four, MAX(CASE WHEN LEVEL = 5 THEN LEVEL END) AS five FROM DUAL CONNECT BY LEVEL &lt;= 5 </code></pre> <p>The aggregate function MAX is necessary to "flatten" the resultset into a single row/record.</p> <p>If you got this far, you're thinking "but I don't want to have to specify for every column--I want it to be dynamic based on <em>i</em>...". There's two issues:</p> <ol> <li>There is a limit to the number of columns - see <a href="http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96525/e1500.htm#1001271" rel="nofollow">ORA-01792 maximum number of columns in a table or view is 1000</a>. That goes for 8i &amp; 9i, anyways. And frankly, needing to generate that many columns raises serious questions about what you're trying to do with the resultset, if there might be a better approach...</li> <li><a href="http://download.oracle.com/docs/cd/B10500_01/appdev.920/a96590/adg09dyn.htm" rel="nofollow">Dynamic requirements means using dynamic SQL</a></li> </ol>
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    1. POsql query on dual
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    1. COYes, Your guess is absolutely correct. I want to select columns dynamically.Thanks
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    2. COThere's nothing wrong with this answer, I just wanted to add that the query is functionally equivalent to `select 1,2,3,4,5 from dual`.
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