在conditon相關的查詢中的Mysql

SELECT ac1.id, ac1.course_name, case when a.yettoapprove is not null 
then 'true' 
else 'false' 
end OrderedAll , a.* from (SELECT ac.id, sum(case when ad.status = '2' then 1 else 0 end) as yettoapprove , sum(case when ad.status = '1' then 1 else 0 end) as approved,case when ad.status = '2' is not null 
then 'true' 
else 'false' 
end OrderedAll FROM aw_ou_student_data ad , jos_users ju , aw_ou_lookup_courses ac,aw_ou_lookup_colleges ac1 where ac1.id=ju.college_code and ac.id in (27,28,29,30,133,32,33,34,35,36,37,38,39,40,41,42,43,44,134,135) and ac.school_id=2 and ju.id=ad.user_id and ac.id=ju.course_code GROUP BY ac.id ORDER BY ac.id) a left join aw_ou_lookup_courses ac1 on ac1.id = a.id

在上面的內部查詢中，我已經給出了20 ac.id但我只有14條記錄作爲結果。我如何獲得總共20條記錄。即身份證目前在條件，如果它不滿足，那麼我應該記錄與0作爲值旁邊的身份證。在conditon相關的查詢中的Mysql

我該怎麼做..？

來源

2014-01-28 sandy

一個簡單的左與條件加入應該這樣做：

SELECT 
    table1.id, 
    table2.* 
FROM 
    table table1 
    LEFT JOIN table2 ON table1.id = table2.id AND (your conditions here)

來源

2014-01-28 06:30:50

我沒有在上面的查詢同樣的事情，但它仍然是不來了。我在哪裏出錯在上面的查詢.. – sandy

在conditon相關的查詢中的Mysql

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