How to print the SQL statement that is being sent to the database?

Question

I would like to know how to printout an SQL for the purpose of controlling the statement being sent to the database:

$sql = $pdo->query("SELECT * FROM imovel WEHRE CATEGORIA = 'APARTAMENTO'");

How to print the SQL statement being sent to the database?

Answer 1

Thus

echo $sql ->queryString

Answer 2

Based on that question, I created a class to see the values of a Prepared statement, basically replacing the placholders with the values. In example is shown how to call the class.

<?php

class queryDebugger{
    const QUESTION_MARK = '/\?/';
    const NAMED_PLACE_HOLDER = '/:[a-z0-9_]+/i';

    private $placeHolder;

    public function setValues($query, $values){

        if(count($values) == 0)  throw new exception('Empty values');

        $this->setplaceHolder($query);
        $placeHolder = array_fill(0, count($values), $this->placeHolder);
        preg_match_all($this->placeHolder, $query, $queryPlaceHolders);

        if(count($placeHolder) != count($queryPlaceHolders[0])){
            throw new exception ('The number of placeholders does not match with values in: ' .$query. ' values: '.count($placeHolder));
        }

        $newQuery = preg_replace($placeHolder, $values, $query, 1);

        return $newQuery;
    }

    private function setPlaceHolder($query){
        (preg_match(queryDebugger::QUESTION_MARK, $query)) ? 
           $this->placeHolder = queryDebugger::QUESTION_MARK :
           $this->placeHolder = queryDebugger::NAMED_PLACE_HOLDER;
    }

}

The method setValues() works as follows first find out what kind of markup is a question mark(?) or a name(:param), array_fill() create an array where the elements are the regex of the markups(/\?/ or /:[a-z0-9_]+/i) afterward preg_match_all returns an array(third parameter) of all occurrences found in $query.

 $newQuery = preg_replace($placeHolder, $values, $query, 1);

preg_replace() replaces the markings with their values the number one (last parameter) is the limit of substitutions that must be made.