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POGetting a folder ID in as few SQL statements as possible
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9990728
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10529762
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2012-04-03T09:41:41.290
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2012-05-10T08:24:00.557
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Consider the database table: folders <pre> folders id parent_id name 1 0 a 2 1 b 3 2 c </pre> 'b' is a folder inside 'a' and thus it's parent_id is the id of 'a'. Folders with a parent_id of 0 simply means it's in the root folder. I wrote a recursive function in php that helps me get the ID of a path that I'm interested in. For example: <pre><code>echo get_folder_id('a/b/c'); // 3 (3 SQL queries) echo get_folder_id('a'); // 1 (1 SQL query) echo get_folder_id('a/b'); // 2 (2 SQL queries) echo get_folder_id('a/c'); // false (2 SQL queries) </code></pre> Problem: For each folder in the path, I had to make a SQL query to the DB server. Question: Is there a way I can reduce the number of queries if the path is 'a/b/c'? Here's my current working solution for reference. <pre><code>function get_folder_id($path, $parent_id=0) { $path = explode('/', $path); $id = 0; //if there's only 1 folder in the path, query the database for the ID if (count($path) == 1) { $rs = $this->db->select('id') ->from('folders') ->where('name', $path[0]) ->where('parent_id', $parent_id) ->limit(1) ->get(); if ($rs->num_rows() == 0) return FALSE; $result = $rs->row_array(); return $result['id']; } foreach($path AS $i=>$p) { if ($i==0 && $p=='') continue; //if a path starts with / move on to the next item $id = $this->get_folder_id($p, $id); } return $id; } </code></pre> Note: I'm using CodeIgniter framework but this isn't related to my question. Just for folks wondering why I used $this->get_folder_id() and $this->db
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Getting a folder ID in as few SQL statements as possible
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