即使連接表爲空也顯示行嗎？

Question

如果我找回場館與他們的關閉時間從另一個表像這樣的列表：

$fullDate = date('Y-m-d H:i:s'); 

$query="SELECT 
venues.ID, 
venues.VENUE_NAME, 
locations.LOCATION, 
hrs.opening_day, 
hrs.opening_time, 
hrs.closing_time 
FROM venues 
INNER JOIN venue_types 
ON venues.VENUE_TYPE = venue_types.ID 
INNER JOIN locations 
ON venues.VENUE_LOCATION = locations.ID 
INNER JOIN hours_of_operation hrs 
    on hrs.venue_id = venues.id 
    and ((hrs.opening_day=date_format('$fullDate' - INTERVAL (closing_time<opening_time and time('$fullDate')<closing_time) DAY, '%a'))) 
GROUP BY venues.VENUE_NAME"; 

我得到的，我已經指定了打開/關閉時間某一天在hours_of_operation場館的結果。無論當天hours_of_operation行是否爲空，該如何顯示所有場所？

謝謝！ :)

Answer 1

使用LEFT JOIN：

... 
LEFT JOIN hours_of_operation hrs 
...