Mysql查詢組合

我有一個由3個表a，b，c組合而成的查詢，這裏的問題是表c存在於2個數據庫D1和D2中，所以我必須從兩個數據庫中爲表獲取記錄ç。表a和b是從單獨的數據庫D1，Mysql查詢組合

查詢是：

$strQuery="SELECT a.id, b.lastname, school " ."FROM D1.a,D1.b" . 
    " WHERE a.idint = (select c_idint from D1.c where Cid IN(10) 
UNION select c_idint from D2.c where Cid IN(10) order by c_idint) 
AND a.idint = b.idb";

的問題是場「學校」是表C，如果我避免查詢外地「學校」它工作正常，但我也必須獲取「學校」字段，我如何修改查詢。謝謝:)

來源

2013-06-25 Yip Man WingChun

使用'AS'到你的別名'D1.c'表到別的 – naththedeveloper

*這是*的問題？怎麼樣在這個查詢中發生的所有其他垃圾 - 如果子查詢返回一個數組，以及停止和開始（「。」）是什麼？ – Strawberry

@Strawberry，在你喊之前請想想 –

試試這個：

$strQuery="SELECT a.id, b.lastname, c.school as dSchool, '' as ddSchool " ."FROM D1.a,D1.b, D1.c" . 
    " WHERE a.idint = c.idint AND c.Cid IN (10) 
AND a.idint = b.idb 

UNION 

SELECT a.id, b.lastname, '' as dSchool, c.school as ddSchool " ."FROM D1.a,D1.b, D2.c" . 
    " WHERE a.idint = c.idint AND c.Cid IN (10) 
AND a.idint = b.idb 
";

來源

2013-06-25 07:43:57 dArc

完美...完美.. –

你需要的是alias，

$strQuery="SELECT a.id, b.lastname, D2.c.school as school1,D1.c.school as school2 " ."FROM D1.a,D1.b,D1.c,d2.c" . 
      " WHERE a.idint = (select c_idint from D1.c where Cid IN(10) 
      UNION select c_idint from D2.c where Cid IN(10) order by c_idint) 
      AND a.idint = b.idb";

來源

2013-06-25 07:21:44 Rikesh

應該有一個'從表c'部分也在查詢右邊，但它從2個數據庫 –

其給出錯誤 –

什麼錯誤？我指導你，你想在我的查詢中更改數據庫或表名。 – Rikesh

給一個嘗試這樣的： -

$strQuery="SELECT a.id, b.lastname, c.school " ."FROM D1.a,D1.b,D1.c" . 
" WHERE a.idint = (select c_idint from D1.c where Cid IN(10) 
UNION select c_idint,school from D2.c where Cid IN(10) order by c_idint) 
AND a.idint = b.idb";

來源

2013-06-25 07:32:02

，但是表c是從2個數據庫D1和D2獲取的 –

@YipManWingChun在查詢學校中從數據庫D1和D2中獲取 –

否，您將查詢作爲「」從D1獲取。 a，D1.b，D1.c「」沒有D2.c？ –

回答

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