รูปแบบคำสั่งการ JOIN TABLE 4 TABLE JOIN TABLE course,sector,program เข้ามาที่ table information_student

<?php
		 		$sql = "SELECT.*,
				sector.sector_name,
				program.program_name,
				course.course_name
				FROM  information_student
				Inner Join course_id  ON information_student.course_id = information_student.course_id
				Inner Join sector  ON sector.sector_id = information_student.sector_id
				Inner Join program ON program.program_id = information_student.program_id
	
				WHERE
				sector.sector_id =  '$sector_id'
				program.program_id =  '$program_id'
				course.course_id =  '$course_id'";
			
		  $db_query = mysql_db_query($dbname,$sql);
           $nums_rows = mysql_num_rows($db_query);
			for ($i=0;$i<$nums_rows;$i++)
                    {
	       	$result=mysql_fetch_array($db_query);
	 		$sector_id = $result[sector_id];
			$sector_name = $result[sector_name];
			$program_id = $result[program_id];
			$program_name = $result[program_name];
			$course_id = $result[course_id];
			$course_name= $result[course_name]; 
			$username= $result[username]; 
			$name= $result[name]; 
		     }
			?>