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POSelecting a node in the nested set model through a not-unique name
 

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  1. POSelecting a node in the nested set model through a not-unique name
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    <p>I am trying to manage the retrieval of a node in a <a href="http://mikehillyer.com/articles/managing-hierarchical-data-in-mysql/" rel="nofollow">nested set model</a> table, not through the unique ID, but <strong>through the name</strong> (a string), and other nodes within the tree under different parents may be called the same way.</p> <p>As far as now I used an unique ID to get nodes inside the nested sets:</p> <pre><code>SELECT node.name, node.lft, node.rgt FROM tbl AS parent, tbl AS node WHERE node.lft BETWEEN parent.lft AND parent.rgt AND node.id = '{$node_id}' GROUP BY node.id</code></pre> <p>Trying to extend this method to a more general way to retrieve the node through its name, I came up with a query containing as much HAVING clauses as the depth of the node to retrieve, checking for the node name and its depth:</p> <pre><code>SELECT node.name, node.lft, node.rgt, COUNT(node.id) AS depth FROM tbl AS parent, tbl AS node WHERE node.lft BETWEEN parent.lft AND parent.rgt GROUP BY node.id HAVING (node.name = 'myParentName' AND depth = 1) OR (node.name = 'myParent2Name' AND depth = 2) OR ... # and so on </code></pre> <p>But it is not perfect: having two nodes with the same name and the same depth, but within different parents, both are retrieved, no matter the hierarchy they belong to.</p> <p>Example:</p> <pre> ARTICLES | +--PHP | +--the-origins | +--syntax +--JS +--history +--syntax </pre> <p>In this case, the query above would return either ARTICLES/PHP/syntax or ARTICLES/JS/syntax: a "syntax" node with depth 3, infact, is either under the PHP node or under the JS node. Is there an effective path to walk, to solve this problem?</p>
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    1. USEmanuele Del Grande
    1. USEmanuele Del Grande
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      1. VTUpMod
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      1. USuser1428644
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      1. VTUpMod
    1. COSo, you're inputting for instance 'PHP' & 'syntax' and their respective depths, and you want their trail to the top? Or what is the exact input & output you want if that isn't the case?
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      1. USWrikken
    2. COYes Wrikken, I am trying to do exactly that. I would take the depth from the given path.
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      1. USEmanuele Del Grande
 

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