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Author MySQL LIKE
Steve
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Registered: 30th Mar 02
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22nd Oct 07 at 08:22   View Garage View User's Profile U2U Member Reply With Quote

Iv rewritten the showroom search on vagweb so it now search on image tags. These are seperated in the DB by commas or spaces.

This works fine using the LIKE % $query % statement. So for example if my image has the tags silver, skoda, fabia, vrs then searching for silver skoda, or fabia vrs brings it up fine. But if i search for two tags that arent next to each other in line, ie silver vrs, then it doesnt find it.

Is there any query i can use that brings up any instances of the words anywhere in the line?
James
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22nd Oct 07 at 08:27   View User's Profile U2U Member Reply With Quote

A dirty way of doing it would be to split the search string at code level and then pass in say 6 different parameters to the query, you would have to guess how many words the longest search would be though.
AndyKent
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22nd Oct 07 at 08:40   View User's Profile U2U Member Reply With Quote

You can count the number of words entered (received by the search page) and build the query around the number of arguments, not sure how accurate the search results would be though....
Steve
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22nd Oct 07 at 14:51   View Garage View User's Profile U2U Member Reply With Quote

hmmz
Ian
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22nd Oct 07 at 15:15   View Garage View User's Profile U2U Member Reply With Quote

Nothing wrong with splitting the queries and a load of OR WHERE, apart from perhaps a bit of speed.

FULLTEXT is also an option.
Laney
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22nd Oct 07 at 15:59   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by Ian
Nothing wrong with splitting the queries and a load of OR WHERE, apart from perhaps a bit of speed.

FULLTEXT is also an option.


Replaces spaces in the searchphrase with %'s?

FULLTEXT is a bit fiddley is it not? Especially when he'd have to change the INI settings to get past the min 4chars rule. Definately a slicker option though
Ian
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22nd Oct 07 at 16:01   View Garage View User's Profile U2U Member Reply With Quote

Replacing space with % wouldn't fix the ordering issue of each of the search queries.
Steve
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22nd Oct 07 at 16:01   View Garage View User's Profile U2U Member Reply With Quote

came up with this

code:

$words = split(" ", $s);
$count = count(explode(" ", $s));
$c='0';
while ($c < $count)
{
$or = $or . "OR " . $where . " LIKE '%" . $words[$c] . "%' ";
$c++;
}

$sql = "SELECT p.pic_id, p.pic_title, p.pic_desc, p.pic_user_id, p.pic_username, p.pic_time, p.pic_cat_id, p.pic_approval, p.pic_file_name, p.pic_thumbnail, c.cat_id, c.cat_title, c.cat_user_id
FROM " . ALBUM_TABLE . ' AS p,' . ALBUM_CAT_TABLE . " AS c
WHERE p.pic_approval = 1
AND " . $where . " LIKE '%" . $s . "%'
$or
AND p.pic_cat_id = c.cat_id
AND c.cat_view_level <> '3'
ORDER BY p.pic_time DESC";


it works, but can anyone see anything thats likely to cause things to grind to a halt there with a large query?
James
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22nd Oct 07 at 16:04   View User's Profile U2U Member Reply With Quote

That's pretty much what I was getting at.

How big is the query that's breaking it?

Also, what is $where?
Steve
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22nd Oct 07 at 16:05   View Garage View User's Profile U2U Member Reply With Quote

$where is just something that changes when you select the search query type, at the moment the options are, Username, Image Title, and Image Tags
James
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22nd Oct 07 at 16:06   View User's Profile U2U Member Reply With Quote

Is there a limit on the length of a PHP string? I'm not hot on PHP. C# FTW

Can you trace out the SQL thats crashing and then run it directly in MySQL to see if its a DB or Code issue?

Steve
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22nd Oct 07 at 16:08   View Garage View User's Profile U2U Member Reply With Quote

quote:
Originally posted by James
Is there a limit on the length of a PHP string? I'm not hot on PHP. C# FTW

Can you trace out the SQL thats crashing and then run it directly in MySQL to see if its a DB or Code issue?




its not crashing, it works fine i just wondered if any eagle eyed bodies could forsee that becoming slow with more requests
James
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22nd Oct 07 at 16:10   View User's Profile U2U Member Reply With Quote

Not as long as your as DB is designed well. Realistically no-one is going to input a huge string anyway apart from muppetsport

P.s. Thanks for a snippet of your DB structure for SQL injection xxx
Steve
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22nd Oct 07 at 16:19   View Garage View User's Profile U2U Member Reply With Quote

no worries, shame you dont know my table names

iv got another problem, now i have that list of OR's being created its ignoring my ANDS

any ideas?
James
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22nd Oct 07 at 16:23   View User's Profile U2U Member Reply With Quote

Put all the ORs in brackets and use an AND for the group. Like this:

Criteria1 = 1 AND Criteria2 = 2 AND (Criteria3 = 3 OR Criteria4 = 4)

[Edited on 22-10-2007 by James]
Steve
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22nd Oct 07 at 16:26   View Garage View User's Profile U2U Member Reply With Quote

yeah just figured that out lolz
Ian
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22nd Oct 07 at 17:54   View Garage View User's Profile U2U Member Reply With Quote

I would imagine it is slow just simply because of all the ORs. There's no real way around that as you can't index your way out of a substring.
Steve
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22nd Oct 07 at 18:06   View Garage View User's Profile U2U Member Reply With Quote

nah its not slow at the moment, but iv only tried a few simply queries, just wondering if you could see it being slow in the future?
Ian
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23rd Oct 07 at 03:00   View Garage View User's Profile U2U Member Reply With Quote

More data and more words in your query, yes.
Steve
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23rd Oct 07 at 06:01   View Garage View User's Profile U2U Member Reply With Quote

best way to avoid> limit the query length?
AndyKent
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23rd Oct 07 at 07:40   View User's Profile U2U Member Reply With Quote

I'd just limit it to, say, 5 words. But don't tell the users that it only searches for 5 words......just drop any extra words from the search.
Steve
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23rd Oct 07 at 08:38   View Garage View User's Profile U2U Member Reply With Quote

yak theres still issues.

my problem now is if i search for

green seat arosa

it will pull up everything with green | seat | arosa in the tags.

so it pulls up all the ibizas, and leons etc, i want it to only get the green arosas

fuck

[Edited on 23-10-2007 by Steve]
Steve
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23rd Oct 07 at 08:49   View Garage View User's Profile U2U Member Reply With Quote

i need it to get all the queries in the search string, but that can be anywhere in the string
Steve
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23rd Oct 07 at 09:31   View Garage View User's Profile U2U Member Reply With Quote

no worries its sorted
James
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23rd Oct 07 at 09:38   View User's Profile U2U Member Reply With Quote

Your ORs needed to be ANDs?

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