mysql數據庫兩表關聯查詢統計同一字段不同值的個數

數據表如下：

統計總數

SELECT h.*,IFNULL(count(r.pid),0) AS 總數
FROM rts_room AS r RIGHT JOIN rts_house AS h
ON r.pid = h.Id
AND r.state != 3
WHERE h.state = 0
GROUP BY h.Id

輸出結果如下：

統計總數及閑置的個數

SELECT 
h.*,
SUM(CASE r.state WHEN "0" THEN 1 ELSE 0 END)+
SUM(CASE r.state WHEN "1" THEN 1 ELSE 0 END) AS 總數,
SUM(CASE r.state WHEN "0" THEN 1 ELSE 0 END) AS 閑置
FROM rts_room AS r RIGHT JOIN rts_house AS h
ON r.pid = h.Id
WHERE h.state = 0
GROUP BY h.Id

輸出結果如下：