ตรงนี้ครับ
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$sql_penalties = mysql_query("SELECT *
                                        FROM tbl_penalties
                                        LEFT JOIN tbl_teams ON(tbl_teams.team_id=tbl_penalties.team_id)
                                        LEFT JOIN tbl_players ON(tbl_players.player_id = tbl_penalties.player_id)
                                        WHERE schdule_id = $schedule_id");

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มันไม่ได้ใส่ team_id ที่รับค่ามาครับ