PHP - Generate write query (insert....) from SELECT mysql

createWriteQuery.php

<?php
class PDO2 extends PDO {
	private static $_instance;
	/* Constructeur : héritage public obligatoire par héritage de PDO */
	public function __construct( ) {
	
	}
	// End of PDO2::__construct() */
	/* Singleton */
	public static function getInstance() {
	
		if (!isset(self::$_instance)) {
			
			try {
			
				self::$_instance = new PDO(SQL_DSN, SQL_USERNAME, SQL_PASSWORD);
			
			} catch (PDOException $e) {
			
				echo $e;
			}
		} 
		return self::$_instance; 
	}
	// End of PDO2::getInstance() */
}

/**
 * Generate Write Query (INSERT, UPDATE, DELETE)
 *
 * @param String $sql
 * @param bool $bIgnore - if false do not add IGNORE
 *
 * @return string
 */
function createWriteQuery($sql, $action = 'insert', $bIgnore = false)
{
    $aFields = [];
    $aMetaFields = [];

    $pdo = PDO2::getInstance();
    $res = $pdo->prepare($sql);
    $res->execute();

    // columns count inside fields
    $nb = $res->columnCount();

    // results rows count
    $nbRows = $res->rowCount();

    // First meta
    $aCol0 = $res->getColumnMeta(0);
    $sTablename = array_key_exists('table', $aCol0) ? $aCol0['table'] : '';

    // columns fields
    for ($i = 0; $i < $nb; $i++) {
        $aCol = $res->getColumnMeta($i);
        array_push($aMetaFields, $aCol);
        $name = array_key_exists('name', $aCol) ? $aCol['name'] : '';
        if ($name !== '') {
            array_push($aFields, $name);
        }
    }
    $aFields = array_map(function ($v) {
        return "`" . $v . "`";
    }, $aFields);
    $sFields = implode(', ', $aFields);


    // All Rows
    $aValues = [];
    while ($row = $res->fetch(3)) {


        $i = 0;
        foreach ($aMetaFields as $meta) {

            $flagsExists = array_key_exists('flags', $meta) && count($meta['flags']) > 0 ;
            $aRow = $row[$i];

            // flag exists - field is not null
            if ($flagsExists) {
                $aRow = $aRow !== '' ? "'" . str_replace("'","\'",$aRow) . "'" : "''";
            } else {
                $aRow = !is_null($aRow) ? "'" . str_replace("'","\'",$aRow) . "'" : 'NULL';
            }

            // populate row
            $row[$i]  = $aRow;

            $i++;
        }


        // implode rows
        $srValues = implode(', ', $row);

        // Create sql
        $sql = "INSERT "; // Todo add UPDATE, DELETE 

        if ($bIgnore && $action === 'insert') {
            $sql .= " IGNORE INTO ";
        }
        if (!$bIgnore && $action === 'insert') {
            $sql .= " INTO ";
        }

        $sql .= " `" . $sTablename . "`";
        if ($action === 'insert') {
            $sql .= " (" . $sFields . ") VALUES (" . $srValues . ");";
        }

        // Implode values
        array_push($aValues, $sql);
    }
    $sql = implode("\n", $aValues);

    if ($nbRows === 0) {
        $sql = ' -- no rows : ' . $sTablename ;
    }
    if ($nbRows > 0) {
        $sql = '-- ' . $sTablename . ' : ' .$nbRows . ' rows ' ."\n -- \n " . $sql;
    }

    return $sql;
}


// Usage
$sql = "SELECT * FROM mytable";
$sqlG = createWriteQuery($sql);
var_dump($sqlG);
// Return INSERT INTO mytable(id,name) VALUES(1,'bob');