How to find a bad query - Page 2

		vb.org Archive > vBulletin Article Depository > Read An Article > vBulletin 3 Articles
How to find a bad query

Page 2 of 2

Thread Tools

JJR512

Join Date: Oct 2001

Posts: 710

Glen Burnie, MD, USA

JJR512

02-23-2002, 10:00 PM

I've been testing a hack I've been working on. At one point during the testing, I received a MySQL error message stating there was a problem with a query. It said what the query was, but as you've probably noticed in these error messages, it only gives a line number of '1'. The problem here was that I had four of the exact same query throughout the code, and I couldn't tell which one was causing the problem.

The specific problem was that in the WHERE part, it was written like "WHERE field=$variable", and $variable didn't have a value. The problem really wasn't the query itself, it was the code before it that was supposed to generate a value for $variable.

So the problem was how to quickly find out which of the four identical queries had some bad code before it. Then I realized how to do it. In the first query, I put a "and 1=1" at the end of the WHERE part, so it was like "WHERE field=$variable and 1=1". For the next one, I did 2=2, and so on, for all four.

Because 1 always equals 1, putting that bit in has absolutely no effect whatsoever on how the code or query works. Basically, you're putting it there as a marker.

This way, when the error message showed up and the query was quoted, it would include the marker (the "and x=x" part), and that would show me which query had the bad code before it.

Maybe this was basic or nothing new for a lot of you, but I'm still kind of new at this, and I'm glad I figured it out before I had to carefully examine all the code I would have had to look at, because that would have been a pain in my ass.

But if this helps even just one of you, it was worth it for me to post this.

#12

05-08-2006, 02:19 AM

Code Monkey Code Monkey is offline

Join Date: May 2004

Posts: 1,080

Благодарил(а): 0 раз(а)

Поблагодарили: 0 раз(а) в 0 сообщениях

Can vb.org please install the hack that closes old threads. This is an epidemic.

Page 2 of 2

« Previous Thread | Next Thread »

Posting Rules
You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is Off Forum Rules

Forum Jump

All times are GMT. The time now is 02:04 PM.

X vBulletin 3.8.12 by vBS Debug Information
Page Generation 0.03939 seconds Memory Usage 2,194KB Queries Executed 16 (?)
More Information
Template Usage: (1)SHOWTHREAD (1)ad_footer_end (1)ad_footer_start (1)ad_header_end (1)ad_header_logo (1)ad_navbar_below (1)ad_showthread_beforeqr (1)footer (1)forumjump (1)forumrules (1)gobutton (1)header (1)headinclude (1)modsystem_article (1)navbar (4)navbar_link (120)option (1)pagenav (1)pagenav_curpage (1)pagenav_pagelink (2)post_thanks_box (2)post_thanks_button (1)post_thanks_javascript (1)post_thanks_navbar_search (2)post_thanks_postbit_info (1)postbit (2)postbit_onlinestatus (2)postbit_wrapper (1)spacer_close (1)spacer_open (1)tagbit_wrapper Phrase Groups Available: global inlinemod postbit posting reputationlevel showthread	Included Files: ./showthread.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/functions_bigthree.php ./includes/class_postbit.php ./includes/class_bbcode.php ./includes/functions_reputation.php ./includes/functions_post_thanks.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 showthread_start showthread_getinfo forumjump showthread_post_start showthread_query_postids showthread_query bbcode_fetch_tags bbcode_create showthread_postbit_create postbit_factory postbit_display_start post_thanks_function_post_thanks_off_start post_thanks_function_post_thanks_off_end post_thanks_function_fetch_thanks_start post_thanks_function_fetch_thanks_end post_thanks_function_thanked_already_start post_thanks_function_thanked_already_end fetch_musername postbit_imicons bbcode_parse_start bbcode_parse_complete_precache bbcode_parse_complete postbit_display_complete post_thanks_function_can_thank_this_post_start pagenav_page pagenav_complete tag_fetchbit_complete forumrules navbits navbits_complete showthread_complete
Messages:

The Arcive of Official vBulletin Modifications Site.

It is not a VB3 engine, just a parsed copy!