SQL DB2查询错误

Question

I'm trying to get a hang on SQL, but I dont know why this doesn't work.

    SELECT p.Ort, COUNT(Projekt.Ort) AS Anzahl
    FROM Projekt p
    WHERE Anzahl > 2 GROUP BY p.Ort;

If I try to use this I get:

    "ANZAHL" is not valid in the context where it is used.. SQLCODE=-206, SQLSTATE=42703, DRIVER=4.9.78

Answer 1

In GROUP BY clauses, the HAVING keyword is used:

SELECT p.Projektort, COUNT(Projekt.Projektort) AS ProjektAnzahl
FROM Projekt p
GROUP BY p.Projekt
HAVING ProjektAnzahl > 2 

Answer 2

You should HAVING instead of WHERE

  SELECT p.Projektort, COUNT(Projekt.Projektort) AS ProjektAnzahl
  FROM Projekt p
  GROUP BY p.Projektort
  HAVING COUNT(Projekt.Projektort) > 2 ;