View and debug prepared PDO query without looking at MySQL logs - php

Question

I want to see what PDO is preparing without looking into the MySQL logs. Basically the final query it has built right before it executes the query.
Is there a way to do this?

Answer 1

There is no built-in way to do it. bigwebguy created a function to do it in one of his answers:
/**
* Replaces any parameter placeholders in a query with the value of that
* parameter. Useful for debugging. Assumes anonymous parameters from
* $params are are in the same order as specified in $query
*
* #param string $query The sql query with parameter placeholders
* #param array $params The array of substitution parameters
* #return string The interpolated query
*/
public static function interpolateQuery($query, $params) {
$keys = array();
# build a regular expression for each parameter
foreach ($params as $key => $value) {
if (is_string($key)) {
$keys[] = '/:'.$key.'/';
} else {
$keys[] = '/[?]/';
}
}
$query = preg_replace($keys, $params, $query, 1, $count);
#trigger_error('replaced '.$count.' keys');
return $query;
}

Answer 2

This is just a derivation of #Maerlyn code above which accept non-asociative arrays for params like and where if the key starts already with ':' don't add it.
/**
* Replaces any parameter placeholders in a query with the value of that
* parameter. Useful for debugging. Assumes anonymous parameters from
* $params are are in the same order as specified in $query
*
* #param string $query The sql query with parameter placeholders
* #param array $params The array of substitution parameters
* #return string The interpolated query
*
* #author maerlyn https://stackoverflow.com/users/308825/maerlyn
*/
function interpolateQuery($query, $params) {
$keys = array();
# build a regular expression for each parameter
if (!isAssoc($params)){
$_params = []; // associative array
foreach($params as $param){
$key = $param[0];
$value = $param[1];
// $type = $param[2];
$_params[$key] = $value;
}
$params = $_params;
}
foreach ($params as $key => $value) {
if (is_string($key)) {
$keys[] = '/'.((substr($key,0,1)==':') ? '' : ':').$key.'/';
} else {
$keys[] = '/[?]/';
}
}
$query = preg_replace($keys, $params, $query, 1, $count);
#trigger_error('replaced '.$count.' keys');
return $query;
}