簡單的代碼，SQL

Question

任何機構可以告訴我爲什麼這個代碼不工作，我得到的所有employeegrade爲0

select Fname,lname, salary, salary =( 
    case when salary>0 and salary <5000 then 1 
    when SALARY>5000 and salary <7000 then 2 
    else 3 end) 
employeegrade from employee; 

Answer 1

如果你使用SQL服務器，則在執行給定查詢出現以下錯誤。 「附近'員工等級'的語法不正確。」 原因是你試圖將計算結果分配給兩個不同的列名稱，即。工資和員工等級。

如果要計算員工等級，可以使用下面的查詢。

select Fname,lname, salary, employeegrade =( 
     case when salary>0 and salary <5000 then 1 
     when SALARY>5000 and salary <7000 then 2 
      else 3 end) 
    from employee; 

OR

select Fname,lname, salary, 
     case when salary>0 and salary <5000 then 1 
     when SALARY>5000 and salary <7000 then 2 
      else 3 end as employeegrade 
    from employee; 

Answer 2

試試下面的代碼

select Fname,lname, salary, 
(case when salary>0 and salary <5000 then 1 when salary >5000 and salary <7000 then 2 else 3 end) as employeegrade from employee; 

Answer 3

嘗試刪除salary =這被解釋作爲比較運算符，所以0就是結果。

Answer 4

試試這個

select Fname,lname, salary, 
case when salary > 0 and salary < 5000 then 1 
when SALARY > 5000 and salary < 7000 then 2 
else 3 end as employeegrade 
from employee;