เริ่มต้นสร้าง PHP Lib กันดีกว่า 3

SQLCommand.php
<?php
if (! defined ( "S_CHARACTOR" ))
	define ( "S_CHARACTOR", 1001 );
if (! defined ( "S_NUMERIC" ))
	define ( "S_NUMERIC", 1002 );
if (! defined ( "S_BLOB" ))
	define ( "S_BLOB", 1003 );
if (! defined ( "S_DATETIME" ))
	define ( "S_DATETIME", 1004 );

/** @package Databases */
class SQLCommand {
	/**
	 * array list variable parameter
	 *
	 * @var array
	 */
	private $a_assign_var;
	
	/**
	 * array list value for list parameter
	 *
	 * @var array
	 */
	private $a_assign_value;
	
	/**
	 * Source sql command before parsing sql command.
	 *
	 * @var string
	 */
	private $s_sql_source;
	
	/**
	 * Constructor
	 * $o_ new SQLCommand("select * from tbl1 where col1 = :c_1");
	 * $o_->setValue("c_1","name");
	 * print $o_->parseSQL();
	 *
	 * @param string $s_sql_source
	 */
	function __construct($s_sql_source = '') {
		$this->s_sql_source = $s_sql_source;
	}
	
	/**
	 * Assgin value on mark point from sql command.
	 *
	 * @param string $s_marker
	 * @param string $s_values
	 */
	public function setValue($s_marker, $s_values, $s_col_type = S_CHARACTOR) {
		
		$this->a_assign_var [] = "/:" . $s_marker . "/";
		if ($s_col_type === S_CHARACTOR) {
			$this->a_assign_value [] = "'" . $s_values . "'";
		} else if ($s_col_type === S_DATETIME) {
			$this->a_assign_value [] = "'" . $s_values . "'";
		} else {
			$this->a_assign_value [] = $s_values;
		}
	}
	/**
	 * Set source Sql command.
	 *
	 * @param string $s_sql
	 */
	public function setSql($s_sql = '') {
		$this->s_sql_source = $s_sql;
	}
	
	/**
	 * Get source Sql command.
	 *
	 * @return string
	 */
	public function getSql() {
		return $this->s_sql_source;
	}
	
	/**
	 * Return parsing sql command.
	 *
	 * @return string
	 */
	public function parseSQL() {
		return preg_replace ( $this->a_assign_var, $this->a_assign_value, $this->s_sql_source );
	}
}

?>[/code]

การใช้งาน
[code]UseSQLCommand.php
<?php
include_once "SQLCommand.php";

$s_sql = "INSERT INTO tbl_teacher ( title_name_id, name, middle_name, surname, email, faculty, created_at, updated_at) VALUES( :title_name_id, :name, :middle_name, :surname, :email, :faculty, :created_at, :updated_at);";
print "ก่อน กำหนดค่า<br>";
print $s_sql."<br>";
        $o_sql_cmd = new SQLCommand ( $s_sql );
        $o_sql_cmd->setValue ( 'title_name_id', 1, S_NUMERIC );
        $o_sql_cmd->setValue ( 'name',  "ชื่อ" , S_CHARACTOR  );
        $o_sql_cmd->setValue ( 'middle_name', "ชื่อกลาง", S_CHARACTOR   );
        $o_sql_cmd->setValue ( 'surname',"สกุล", S_CHARACTOR  );
        $o_sql_cmd->setValue ( 'faculty',"วิทยาศาสตร์" , S_CHARACTOR  );
        $o_sql_cmd->setValue ( 'email',  "[email protected]" , S_CHARACTOR  );
        $o_sql_cmd->setValue ( 'created_at', date ( "Y-m-d H:i:s" ), S_DATETIME );
        $o_sql_cmd->setValue ( 'updated_at', date ( "Y-m-d H:i:s" ), S_DATETIME );
print "หลัง กำหนดค่า<br>";
print $o_sql_cmd->parseSQL () ; // จะคืนค่ากลับมาเป็น คำสั่ง Sql ที่สามารถนำไปส่งฐานข้อมูลประมวลผลได้เลย แต่สำหรับตรงนี้ผมให้มันแสดงออกทางหน้าเว็บ
?>