当然。将WHERe条件移动到JOIN:
SELECt pr.*, pr7.value AS `room_price_high` FROM `jos_hp_properties` pr LEFT JOIN `jos_hp_properties2` pr7 ON pr7.property=pr.id AND pr7.field=23

当然。将WHERe条件移动到JOIN:
SELECt pr.*, pr7.value AS `room_price_high` FROM `jos_hp_properties` pr LEFT JOIN `jos_hp_properties2` pr7 ON pr7.property=pr.id AND pr7.field=23