如何从2个访问表

Question

我一直工作在一个访问项目来管理本地的高中足球联赛...

显示所有记录我有2个表： tbl_schools，与字段：

[id_school, school_name] 

和 tbl_penalties，与字段：

[id_penalty, school, player, match, card] 

和查询，query_penalties：

SELECT DISTINCTROW tbl_penalties.school, Count(tbl_penalties.school) AS penalties 
FROM tbl_penalties 
GROUP BY tbl_penalties.school; 

任务/我的问题： 我需要一个查询，以显示（在它的第一列）在tbl_schools所有学校（它是第二列）在学校被处罚的次数，和0，如果学校没有任何处罚......

Answer 1

SELECT S.school_name 
     ,COUNT(P.school) AS penalties 
FROM tbl_schools S LEFT JOIN tbl_penalties P 
ON S.id_school = P.school 
GROUP BY S.school_name 

SELECT S.school_name 
     ,COUNT(P.school) AS penalties 
FROM tbl_schools S LEFT JOIN tbl_penalties P 
ON S.id_school = P.school 
GROUP BY S.school_name