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PODealing with recursion (oracle)
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copied!<p>I'm a having some problems trying to do some business logic for a client (web trading):</p> <p>My client has a table (simplified) like this one:</p> <pre><code>|| ID || OFFERED_PRODUCT_ID || DEMANDED_PRODUCT_ID || || 01 || 34 || 45 || || 01 || 34 || 16 || || 01 || 45 || 57 || || 01 || 47 || 57 || || 01 || 57 || 63 || || 01 || 16 || 20 || </code></pre> <p>Now, the app must show the largest trade chain, a trade chain is defined as the relation within offered and demanded products.</p> <p>This are trade chains: </p> <p>< 34, 45, 57, 63> <34, 16, 20> <45, 57, 63> <47, 57, 63> <57, 63> <16, 20></p> <p>I try to use C# to solve this, but given the volume of data it became impossible. A coworker of mine told recommends me to use recursion. I try to understand what he means, but I'm a client side developer, with no much knowledge of SQL.</p> <p>I did these:</p> <pre><code> select o.OFFERED_PRODUCT_ID, o.DEMANDED_PRODUCT_ID from TRADES o start with o.DEMANDED_PRODUCT_ID = (SELECT MIN(o.DEMANDED_PRODUCT_ID) from TRADES) connect by NOCYCLE prior o.DEMANDED_PRODUCT_ID = o.OFFERED_PRODUCT_ID; </code></pre> <p>I'm trying to start the recursion with the oldest product on the system (with the min identifiers). But It doesn't work. It gave me all the trade chains. I need just the largest one.</p> <p>Heres an output example:</p> <pre><code>OFFERED_PRODUCT_ID DEMANDED_PRODUCT_ID 9920896475501851 59587794888502550724 59587794888502550724 13197303523502765990 13197303523502765990 54010274740204405159 54010274740204405159 14505831337880766413 14505831337880766413 89607128670993987443 89607128670993987443 8802863939059413452 8802863939059413452 7779127922701247342 7779127922701247342 3810800421539873909 3810800421539873909 12423373218147473557 </code></pre>

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