让它count为0的记录也显示出来,做法如下: SELECT use_city, COUNT(CASE WHEN os='Windows 2003 Std'THEN 1 ELSE NULL END) FROM data GROUP BY use_city
让它count为0的记录也显示出来,做法如下: SELECT use_city, COUNT(CASE WHEN os='Windows 2003 Std' THEN 1 ELSE NULL END) FROM data GROUP BY use_city