How to process data?

Question

PHP

Goodnight!
I can't figure out how to process the data.
The bottom line is that there are n-th number of pairs of fields in the form:

<input type="text" name="text[god][1]" value="">
<input type="text" name="text[god][2]" value="">

Where:
god - field name
1, 2 - field values
​​There can be a lot of such pairs, and all of them have unique names, i.e. god.
The task is to process them and display them in the where sql query.
I did it differently, but always if the field [1] does not have a pair, then it takes the value [2] from the field of another field name god:

foreach ($_POST["text"] as $key3 => $value3) {
foreach ($value3 as $key4 => $value4) {
if($value4 != '') { 
if($key4 == 1) $wheres1 = $key3.' >= '.$value4;
if($key4 == 2) $wheres2 = $key3.' <= '.$value4;
}
}

if ($wheres1!='' && $wheres2!='') {
$wheres = '('.$wheres1.' AND '.$wheres2.')';
}else{
if($wheres1!='') $wheres = $wheres1;
if($wheres2!='') $wheres = $wheres2;
}
}

Can you tell me how to handle it well? So that if the field [1] does not have a pair, it does not take a value from another field. And insert it all into the sql query where.
Thanks in advance!!!

Answer 1

To begin with, I would recommend that you familiarize yourself with prepared statements - php.net/manual/ru/pdo.prepared-statements.php
And then, use some kind of query builder, like framework.zend.com/manual/current/en/modules/ zend....
and use it like this:

if ($condition) {
   $query->where('blabla = ?', $blabla)
} else {
   $query->where('foo = ?', $foo);
}

Answer 2

Let's say I collected your request

$test_data['text']['god'][1] = 1234;
$test_data['text']['god'][2] = 5678;
$test_data['text']['cat'][1] = 111;
$test_data['text']['cat'][2] = 222;
$test_data['text']['meow'][2] = 888; // there is only one "meow"

$conditions = [];
foreach ($test_data['text'] as $fieldname => $values) {
  $subconditions = [];
  if (!empty($values[1])) $subconditions[] = $fieldname." >= ".intval($values[1]);
  if (!empty($values[2])) $subconditions[] = $fieldname." <= ".intval($values[2]);
  if(!empty($subconditions)) $conditions[] = '('.implode(' AND ', $subconditions).")\n";
}
$sql = "SELECT * FROM tbl_name\n";
if (!empty($conditions)) $sql .= 'WHERE '.implode(' AND ', $conditions);
echo '<pre>' . $sql;
/*
SELECT * FROM tbl_name
WHERE (god >= 1234 AND god <= 5678)
 AND (cat >= 111 AND cat <= 222)
 AND (meow <= 888)
*/

Demo: codepad.viper-7.com/ukJK5V
But this will only work if you train somewhere on your local server. And in general it is IMPOSSIBLE TO DO SO because sql injections are possible.