ถามเรื่อง mysql select ครับ ช่วยด้วยครับ คือผมต้องการ select ข้อมูลจากตาราง B ตามที่ select ได้จากตาราง A โดยไม่ใช้การ join

$qr=mysql_query("select Id from A where Name like '%".$key."%'");
$rs=mysql_fetch_array($qr);
$id = $rs['Id'];

$qy=mysql_query("select * from B where Id in('".$id."')");

$qr=mysql_query("select Id from A where Name like '%$key%'");

if(mysql_num_rows($qr)>0){
  $rs=mysql_fetch_array($qr);
  $qy=mysql_query("select * from B where Id = '$rs[id]' ");
}

$qr=mysql_query("select Id from A where Name like '%$key%'");

if(mysql_num_rows($qr)>0){
  $val="0";
  while($rs=mysql_fetch_array($qr)){ 
    $val.=",'$rs[Id]' "
  }
  $qy=mysql_query("select * from B where Id  in ($val) ");
}

$qr=mysql_query("select Id from A where Name like '%".$key."%'");
while($rs=mysql_fetch_array($qr))
$id.=",'"$rs['Id']."'"; // ทำให้ข้อมูลให้อยู่ในรูปแบบ ,'1','2','3',4'....
$id=substr($id,1); // ตัด , ตัวแรกออก
$qy=mysql_query("select * from B where Id in(".$id.")");

// Find all boards and categories, as well as related information.  This will be sorted by the natural order of boards and categories, which we control.
	$result_boards = $smcFunc['db_query']('boardindex_fetch_boards', '
		SELECT' . ($boardIndexOptions['include_categories'] ? '
			c.id_cat, c.name AS cat_name,' : '') . '
			b.id_board, b.name AS board_name, b.description,
			CASE WHEN b.redirect != {string:blank_string} THEN 1 ELSE 0 END AS is_redirect,
			b.num_posts, b.num_topics, b.unapproved_posts, b.unapproved_topics, b.id_parent,
			IFNULL(m.poster_time, 0) AS poster_time, IFNULL(mem.member_name, m.poster_name) AS poster_name,
			m.subject, m.id_topic, IFNULL(mem.real_name, m.poster_name) AS real_name,
			' . ($user_info['is_guest'] ? ' 1 AS is_read, 0 AS new_from,' : '
			(IFNULL(lb.id_msg, 0) >= b.id_msg_updated) AS is_read, IFNULL(lb.id_msg, -1) + 1 AS new_from,' . ($boardIndexOptions['include_categories'] ? '
			c.can_collapse, IFNULL(cc.id_member, 0) AS is_collapsed,' : '')) . '
			IFNULL(mem.id_member, 0) AS id_member, m.id_msg,
			IFNULL(mods_mem.id_member, 0) AS id_moderator, mods_mem.real_name AS mod_real_name
		FROM {db_prefix}boards AS b' . ($boardIndexOptions['include_categories'] ? '
			LEFT JOIN {db_prefix}categories AS c ON (c.id_cat = b.id_cat)' : '') . '
			LEFT JOIN {db_prefix}messages AS m ON (m.id_msg = b.id_last_msg)
			LEFT JOIN {db_prefix}members AS mem ON (mem.id_member = m.id_member)' . ($user_info['is_guest'] ? '' : '
			LEFT JOIN {db_prefix}log_boards AS lb ON (lb.id_board = b.id_board AND lb.id_member = {int:current_member})' . ($boardIndexOptions['include_categories'] ? '
			LEFT JOIN {db_prefix}collapsed_categories AS cc ON (cc.id_cat = c.id_cat AND cc.id_member = {int:current_member})' : '')) . '
			LEFT JOIN {db_prefix}moderators AS mods ON (mods.id_board = b.id_board)
			LEFT JOIN {db_prefix}members AS mods_mem ON (mods_mem.id_member = mods.id_member)
		WHERE {query_see_board}' . (empty($boardIndexOptions['countChildPosts']) ? (empty($boardIndexOptions['base_level']) ? '' : '
			AND b.child_level >= {int:child_level}') : '
			AND b.child_level BETWEEN ' . $boardIndexOptions['base_level'] . ' AND ' . ($boardIndexOptions['base_level'] + 1)),
		array(
			'current_member' => $user_info['id'],
			'child_level' => $boardIndexOptions['base_level'],
			'blank_string' => '',
		)
	);