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Showing results for tags 'relational database'.
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firstly, I am not a db programmer. I ply my trade in WordPress stuff, but not in-depth db structuring from scratch. please keep that in mind as I do my best to ask this question? I have made some headway creating two tables that I think will almost, kinda do what I want, which is: Phillips pid1Barnes pid2Moore pid3de Mohrenschildt pid4Oswald pid5 Hunt pid6Sturgis pid7Moore pid3 I've created a (really large) outline in html that simply shows, in effect: Phillips (knows) » Barnes (supervised) » Moore (supervised) » de Mohrenschildt (knows) » Oswald ... AS WELL AS, Phillips (knows) » Hunt (knows) » Sturgis (followed, who also knows) » Moore (same, pid3) ... I put Sturgis followed by Moore specifically to show that these relationships are in no way numerically sequential from the ASSOCS table. There will be 4 or 500 Persons, (and 40 or 50 Organizations, once I get this solved). You can see an example of it here (there's lots of data going on in this outline): http://stemmonsfreeway.com/military-industrial-intelligence-anti-castro-syndicated So, I've come up with these tables: [persons] id, name ----------------- 1 Phillips 2 Barnes 3 Moore 4 de Mohrenschildt 5 Oswald 6 Hunt 7 Sturgis [assocs] p_id, a_id ---------------- 1 2 2 3 3 4 4 5 1 6 6 7 7 3 And I have this query: SELECT a1.p_id, p1.name AS 'Name', a2.p_id, p2.name AS 'FName1', a3.p_id, p3.name AS 'FName2' FROM assocs a1 JOIN assocs a2 ON a1.p_id = a2.a_id JOIN assocs a3 ON a2.p_id = a3.a_id JOIN persons p1 ON a1.p_id = p1.id JOIN persons p2 ON a2.p_id = p2.id JOIN persons p3 ON a3.p_id = p3.id WHERE p1.id = 1 AND p2.id = 2 AND p3.id = 3;which returns: 1 Phillips 2 Barnes 3 Moore *** The problem I have is where a trail ends, Phillips to Oswald, and starts again, Phillips to Hunt to Moore, for instance. *** What I need is a way to define an end to a string of associations and a start of the next one, perhaps with another field or two in the ASSOCS table, or another table... (I'd also love to be able to denote one of a few types of relationships, i.e. "friend" "foe" "supervised" "worked for" ...) *** I'm hoping some kind soul can help me with a query that can do this, and some advice on how to handle it in the tables I've started with...?
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- tables
- relational database
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I am creating a simple social network, and i want the post visible only on its circle of friends but the problem is... let say user_a, user_b, user_c already registered and user_a and user_c connected/friends already and all their posts and comments are visible on their circle but when user_b write a post oh his wall, it's also visible to user_a and user_c which i dont want to happen. I dont know what was wrong on codes below. CREATE TABLE IF NOT EXISTS `user`( `uid` INT(11) AUTO_INCREMENT PRIMARY KEY NOT NULL, `uname` VARCHAR(25) NOT NULL, `pword` CHAR(60) NOT NULL, `fullname` VARCHAR(30) NOT NULL, INDEX(`uname`) ) Engine = InnoDB DEFAULT CHARSET=utf8 COLLATE utf8_general_ci; CREATE TABLE IF NOT EXISTS `friend`( `fid` INT(11) AUTO_INCREMENT PRIMARY KEY NOT NULL, `friend_id` INT(11) NOT NULL, `my_id` INT(11) NOT NULL, `stat` ENUM('0','1') NOT NULL, INDEX(`friend_id`, `my_id`), FOREIGN KEY(`friend_id`) REFERENCES `user`(`uid`) ON UPDATE CASCADE ON DELETE CASCADE ) Engine = InnoDB DEFAULT CHARSET=utf8 COLLATE utf8_general_ci; public function viewFriendIfExistOnTbl($uid) { $query = $this->mysqli->query("SELECT `friend_id` FROM `friend` WHERE `my_id` = '$uid' LIMIT 1"); if ($query->num_rows > 0) { return true; } }
- 6 replies
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- relational database
- php
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