條件單個SQL查詢插入

Question

讓說我有一個名爲表：

EMP(Eid,Ename,ESalary) 

現在我要編寫一個查詢，將更新：

if employee's salary >= 20000 then increment 25% else update 15% salary 

Answer 1

update EMP 
    set ESalary = CASE WHEN salary >= 20000 
         THEN salary * 1.25 
         ELSE salary * 1.15 
         END; 

Answer 2

試試這個：

update emp a set esalrary = 
(select (case when esalary >=20000 then esalary+(esalary*25/100) 
else esalary+(esalary*25/100) end) from emp b where a.eid=b.eid);