How can I remove everything past "LIMIT" from a query? (details inside) - php

Question

I got a few queries built dynamically by my scripts. They usually fit the following template:
SELECT ...
FROM ...
JOIN ...
WHERE ... (lots of filters, search conditions, etc. here) ...
ORDER BY (optional) ...
LIMIT (optional) ... OFFSET (optional)
I want to remove the LIMIT and OFFSET parts from the query. I used
$sql_entitati = implode("LIMIT", explode("LIMIT", $sql_entitati, -1));
to do it but then it hit me: what if there's no LIMIT in the query and what if the only LIMIT is somewhere in the where clauses?
So my question to you is: How can I safely remove everything after the LIMIT key word, without screwing it up if there's no LIMIT and/or there's a "LIMIT" somewhere in the where clause? All this done in php.
A bit of an edit for clarity:
the algorithm i use:
$sql = implode("LIMIT", explode("LIMIT", $sql, -1));
Will work on 99% of the cases. The problem occurs when the "LIMIT" key word at the end is missing, AND there is "LIMIT" written somewhere in the conditions. for example:
SELECT * FROM table WHERE bla = 'SPEED LIMIT' ORDER BY table.a
this is the problem i need to tackle.
Solved using the following algorithm (Credit to techfoobar):
$p = strrpos($sql, "LIMIT");
if($p !== false) {
$q = strpos($sql, ")", $p);
$r = strpos($sql, "'", $p);
$s = strpos($sql, "\"", $p);
if($q === false && $r === false && $s === false)
$sql = substr($sql, 0, $p);
}

Answer 1

You should do something like:
Get the position of the last "LIMIT" - store this position in say, p
Ensure that you do not have a ")" character after p - if so, it is part of some inner query inside a condition etc..
Ensure that you do not have a "'" character after p - if so, it is part of some user input string
If steps 2 and 3 are passed, strip off everything after p
More hints:
For step 1 - use strrpos for the last occurrence of LIMIT
For steps 2 and 3, use strpos with p as the search start offset
For step4, use substr to strip off everything after p

Answer 2

Get the position of LIMIT, check it exists with !==FALSE then substring.
$str = "SELECT X FROM Y JOIN WHERE CONDITIONS ORDER BY ORDERS LIMIT OFFSET";
$pos = strrpos($str,"LIMIT");
if ($pos!==false)
{
$newStr = substr($str,0,$pos);
echo $newStr;
}

Answer 3

Try this aproach
$query = '';
$query .= 'SELECT...';
$query .= 'FROM ...';
$query .= 'JOIN ...';
$query .= 'WHERE...';
if ($limit)
{
$query .= " LIMIT $limit";
}

Answer 4

This may help you...
$str = " SELECT * FROM table WHERE bla = 'SPEED LIMIT' ORDER BY table.a";
$pos = strrpos($str,"LIMIT");
if ($pos!==false)
{
$ok = 1;
if(substr_count($str, '"', $pos) % 2 != 0)
{
$ok = 0;
}
if(substr_count($str, "'", $pos) % 2 != 0)
{
$ok = 0;
}
if(substr_count($str, ")", $pos) > 0)
{
$ok = 0;
}
if($ok == 1)
$str = substr($str,0,$pos);
}
echo $str;