php mysql delete record

[baqup]

Hello,

I am trying to develop a script that would go through a delete duplicate records in a mysql db. I dont want to do the native mysql de-dupicate to new db as that loses indexing and the db is fairly large.

What i tried to do is have it compare the titles of a record and then delete the one with the higher id. It currently prints both the first record and the matching duplicate, but it doesnt seem to actually execute the delete statement as when i go into phpmyadmin i can still see the record. I dont get any errors which is adding to my frusturation.

I hope it is just something simple i am not thinking about that someone more experienced than me can figure out.

I GREATLY appreciate your help!!!

Here is what i have:

$mysql=new MySQL();

$sql="select * from news where left(source_id,1)='b' order by id";
$result=$mysql->query($sql);
print $result->size();
print "<br><br>";
$i=0;
while($row=$result->fetch())
  {
    //$t=addslashes(substr($row['title'],0,30));
    $row['title']=addslashes($row['title']);

$sql="select * from news where title like '$row[title]%' and id>'$row[id]' order by news.id";
$result2=$mysql->query($sql);


while($row2=$result2->fetch() and strlen($row['title'])>20)
  {
    print "$row[title] ******************** $row[id]<br>";
	print "$row2[title] ###############  $row2[id]<br>------------------<br><br>";
	$sql="delete from news where id='$row2[id]'";
    $i++;	
  }

  }

  print $i;

[bradgrafelman]

Few things:

1. When posting PHP code, please use the board's [noparse]

   ..

   [/noparse] bbcode tags as they make your code much easier to read and analyze.

2. [man]addslashes/man should never be used to prepare data for a SQL query (unless it's a last resort when no other DB-specific escaping mechanisms are available). Instead, you should use something like [man]mysql_real_escape_string/man (for string data) or prepared statements (which would be more beneficial in your case, IMHO, since you're repeating the same query with different parameters each time).

3. Numeric data shouldn't be quoted (since quotes delimit strings). This won't really cause any errors in your case, but it's just something to keep in mind.

4. In the inner while() loop, you define a SQL query in the variable $sql but never do anything with it (such as execute it).