vb.org Archive

vb.org Archive (https://vborg.vbsupport.ru/index.php)
-   vB3 Programming Discussions (https://vborg.vbsupport.ru/forumdisplay.php?f=15)
-   -   Driving Me Crazy (MYQL Help Please) (https://vborg.vbsupport.ru/showthread.php?t=176287)

noonespecial 04-16-2008 04:04 AM
Driving Me Crazy (MYQL Help Please)
 
I have a table (links_favorites) with two columns (linkid and userid).

I want to write something that counts the number of matches (in linkid) between two different userids.

So it something that grabs all the linkids from userid A - and then all the linkids from userid B - and then counts all the places where this intersects.

However, I simply can't figure out the best/easiest way to do this.

Could someone help please?

nighthalk 04-16-2008 04:41 AM
I don't have your database to test this. So here you can test it.

Code:
<?php
  $sql="SELECT linkid, userid, FROM links_favorites WHERE MATCH (linkid,userid)";
  $result = mysql_query($sql);
  $resultsnumber = mysql_numrows($result);

echo "$resultsnumber";
?>
Let me know if this works.

noonespecial 04-16-2008 07:35 AM
Problem with this is that I need to be able to specify the userids ...

IE: there are 4 matches in LINKID between userid-A and userid-B

Where would I specify those in this example?

--------------- Added [DATE]1208335849[/DATE] at [TIME]1208335849[/TIME] ---------------

Code:
  $sql="SELECT linkid, userid FROM links_favorites WHERE userid=1083";
  $result = mysql_query($sql); 
  $number1 = mysql_fetch_array($result);
 
  $sql2="SELECT linkid, userid FROM links_favorites WHERE userid=1";
  $result2 = mysql_query($sql2); 
  $number2 = mysql_fetch_array($result2);
 
  $result3 = array_intersect($number1, $number2);
 
  $joined = count($result3);
 
  echo $joined;
Also doesn't work. :(

--------------- Added [DATE]1208335899[/DATE] at [TIME]1208335899[/TIME] ---------------

Code:
    $sql="SELECT linkid FROM links_favorites WHERE userid=1083";
  $result = mysql_query($sql); 
  $number1 = mysql_fetch_array($result);
 
  $myids=implode(",", $number1);
 
  $sql2="SELECT COUNT(linkid) as count FROM links_favorites WHERE userid=1 AND linkid IN (".$myids.")";
  $result2 = mysql_query($sql2); 
  $number2 = mysql_fetch_array($result2);
Also doesn't work. :(

--------------- Added [DATE]1208337252[/DATE] at [TIME]1208337252[/TIME] ---------------

Code:
$fandom = $vbulletin->db->query_read("SELECT *
FROM links_favorites AS links_favorites
LEFT JOIN links_favorites AS favs2 ON (links_favorites.linkid=favs2.linkid)
WHERE links_favorites.userid=".$vbulletin->userinfo['userid']."
AND favs2.userid=".$friend[userid]."
");

$joined= $db->num_rows($fandom);
I think this works ..... ugly.

MoT3rror 04-16-2008 07:37 PM
PHP Code:
$linkcount = $db->query_first("
     SELECT COUNT(linkid) AS linkcount 
     FROM links_favorites 
     WHERE userid IN (1, 2)
"); 

Farcaster 04-16-2008 07:53 PM
If I am understanding your question correctly and you want to know how many links User 1 and User 2 share, then you could use this query:

[SQL]SELECT
COUNT(DISTINCT t1.linkid) AS shared_links
FROM
link_favorites t1
INNER JOIN link_favorites t2 ON
t1.linkid = t2.linkid
WHERE
t1.userid = 1
AND t2.userid = 2[/SQL]

Your inclination to use a self-join in your example is pretty close to the mark, except that you could get duplicates and you might as well let MySQL handle the counting. Also, a left join would return all of user 1's links, whether they matched or not.

Eikinskjaldi 04-17-2008 05:38 AM
or you could use a nested query:

[sql]
select count(distinct linkid) from link_favourites
where userid=1
and linkid in
(select distinct linkid from link_favourites where userid=2)
[/sql]

noonespecial 04-17-2008 05:41 AM
Thank you.


All times are GMT. The time now is 03:17 AM.

Powered by vBulletin® Version 3.8.12 by vBS
Copyright ©2000 - 2025, vBulletin Solutions Inc.

X vBulletin 3.8.12 by vBS Debug Information
  • Page Generation 0.00925 seconds
  • Memory Usage 1,729KB
  • Queries Executed 10 (?)
More Information
Template Usage:
  • (1)ad_footer_end
  • (1)ad_footer_start
  • (1)ad_header_end
  • (1)ad_header_logo
  • (1)ad_navbar_below
  • (4)bbcode_code_printable
  • (1)bbcode_php_printable
  • (1)footer
  • (1)gobutton
  • (1)header
  • (1)headinclude
  • (6)option
  • (1)post_thanks_navbar_search
  • (1)printthread
  • (7)printthreadbit
  • (1)spacer_close
  • (1)spacer_open 
Phrase Groups Available:
  • global
  • postbit
  • showthread
Included Files:
  • ./printthread.php
  • ./global.php
  • ./includes/init.php
  • ./includes/class_core.php
  • ./includes/config.php
  • ./includes/functions.php
  • ./includes/class_hook.php
  • ./includes/modsystem_functions.php
  • ./includes/class_bbcode_alt.php
  • ./includes/class_bbcode.php
  • ./includes/functions_bigthree.php 
Hooks Called:
  • init_startup
  • init_startup_session_setup_start
  • init_startup_session_setup_complete
  • cache_permissions
  • fetch_threadinfo_query
  • fetch_threadinfo
  • fetch_foruminfo
  • style_fetch
  • cache_templates
  • global_start
  • parse_templates
  • global_setup_complete
  • printthread_start
  • bbcode_fetch_tags
  • bbcode_create
  • bbcode_parse_start
  • bbcode_parse_complete_precache
  • bbcode_parse_complete
  • printthread_post
  • printthread_complete