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Merge pull request #8 from taikano/patch-2

left join sufficient
Martin Thoma 12 年之前
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4d1d9c1479
共有 1 个文件被更改,包括 3 次插入3 次删除
  1. 3 3
      documents/musterloesung-db-klausur-b/d3d.sql

+ 3 - 3
documents/musterloesung-db-klausur-b/d3d.sql

@@ -1,6 +1,6 @@
 CREATE VIEW Beratungsanzahl AS (
-    SELECT berater_id, count(DISTINCT Berater.berater_id) AS Anzahl
-    FROM Berater
-    FULL OUTER JOIN Kunden ON Berater.berater_id = Kunden.berater_id
+    SELECT berater_id, COUNT(kb.kunden_id) AS anzahl
+    FROM Berater b
+    LEFT OUTER JOIN Kunden2Berater kb ON b.berater_id = kb.berater_id
     GROUP BY berater_id
 )