有條件地使用oracle中的group by子查詢中的值更新表

Question

問題是將所有員工的工資由5個或多於5個項目工作的50％更新爲30％（> = 3個項目） ，減少20％（> = 1個項目），通過在EMPLOYEE_PROJECT_HISTORY上查詢來執行一個組，可以獲得項目的數量;

我嘗試了這些查詢

update emp set emp.sal= 
case 
when jemp.pcount >=5 then emp.sal+ (emp.sal*50)/100 
when jemp.pcount >=3 then emp.sal+ (emp.sal*30)/100 
when jemp.pcount >=1 then emp.sal+ (emp.sal*20)/100 
else emp.sal+ (emp.sal*20)/100 
end 
from employee emp join (select empno as jempno,count(projectno) as pcount from EMPLOYEE_PROJECT_HISTORY by empno) jemp on emp.empno=jemp.jempno ; 

update employee a set a.sal= case (select count(b.projectno) as pcount from EMPLOYEE_PROJECT_HISTORY b group by b.empno) 
    when b.pcount >5 then 
    a.sal = a.sal+ (a.sal*50)/100 
    when pcount >3 then 
    a.sal = a.sal+ (a.sal*30)/100 
    when pcount >1 then 
    a.sal = a.sal+ (a.sal*20)/100 
    end; 

Answer 1

您將無法更新是否包含GROUP BY子句中的Oracle的加入。您可以使用內嵌子查詢，像這樣：

UPDATE employee e 
    SET sal = sal * (SELECT CASE 
           WHEN COUNT(*) >= 5 THEN 
           1.5 
           WHEN COUNT(*) >= 3 THEN 
           1.3 
           WHEN COUNT(*) >= 1 THEN 
           1.2 
           ELSE 
           1 
          END 
         FROM employee_project_history eph 
        WHERE eph.empno = e.empno);