顯示字符串JOIN語句

Question

我有我要轉換爲字符串取決於它的價值即

select語句我想沿着線的東西：

SELECT SchoolID (IF SchoolID = 1 Convert STRING("London"), IF SchoolID = 2 Convert STRING ("Glasglow") ELSE Convert STRING(new school")), 
L.Location 
FROM Schools SC 
Join Location L 
On L.LocationID = SC.LocationID 
Where SchoolID < 200 

不知道如何解決這個問題。

非常感謝， 山姆

- 編輯括號內是我應該看不實際的代碼的語法

Answer 1

可以使用CASE表達這樣的：

SELECT SchoolID 
, case SchoolID 
    when 1 then 'London' 
    when 2 then 'Glasglow' 
    else  'new school' 
    end as SchoolName 
, L.Location 
FROM Schools SC 
Join Location L 
On L.LocationID = SC.LocationID 
Where SchoolID < 200 

Answer 2

SELECT SchoolID, CASE SchoolID 
WHEN 1 THEN 'London' 
WHEN 2 THEN 'Glasglow' 
ELSE 'new school' 
END AS New_Value , 
L.Location 
FROM Schools SC 
Join Location L 
On L.LocationID = SC.LocationID 
Where SchoolID < 200 

Answer 3

案例語句也可以寫成這樣：

SELECT SchoolID, 
     CASE WHEN SchoolID = 1 THEN 'London' 
     WHEN SchoolID = 2 THEN 'Glasglow' 
     ELSE 'new school' 
     END AS city , 
     L.Location 
FROM Schools SC 
JOIN LOCATIONL ON L.LocationID = SC.LocationID 
WHERE SchoolID < 200