更新記錄 - SQL SERVER

Question

我原來的表有這樣一個值：下面我執行下面的查詢

ID   TELPHONE 
    ----------- -------------- 
    1923  6276572 
    1949  2126670825 
    2125 
    1926  12126670825 

得到預期的結果：

UPDATE #T 
SET  TELEPHONE = CASE 
        WHEN CHARINDEX('1212', TELEPHONE, 1) = 0 THEN 
    '1212'+TELEPHONE 

     WHEN CHARINDEX('212', TELEPHONE , 1) = 1 THEN '1'+TELEPHONE 

     ELSE TELEPHONE 

       END 
WHERE (STATE LIKE '%UU%' OR STATE LIKE '%U&P%' OR STATE LIKE '%UTTER%') AND 
LEN(TELEPHONE) <= 10 

我的意料：

ID   TELPHONE 
----------- -------------- 
1923  12126276572 
1949  12126670825 
2125 
1926  12126670825 

但是，我越來越喜歡以下（這是錯誤的）

id  TELPHONE  
----------- -------------- 
    1923  12126276572 
1949  12122126670825    
2125  1212       
1926  12126670825 

我做錯了什麼。以及如何得到預期的結果？

Answer 1

我沒有正確更新與此（我省略你的地方的條件）：

UPDATE TELE SET TELPHONE = CASE WHEN CHARINDEX('212', TELPHONE , 1) = 1 THEN '1'+TELPHONE 
           WHEN CHARINDEX('1212', TELPHONE, 1) = 0 AND TELPHONE<>'' THEN '1212'+TELPHONE        
         ELSE TELPHONE 
         END 

; 輸出：

+------+-------------+ 
| ID | TELPHONE | 
+------+-------------+ 
| 1923 | 12126276572 | 
| 1949 | 12126670825 | 
| 2125 |    | 
| 1926 | 12126670825 | 
+------+-------------+ 

我覺得表演會更好，如果你可以添加到WHERE條件以及電話<>'和簡化的情況下（卸下和第二，當我的情況下）：

UPDATE TELE SET TELPHONE = CASE WHEN CHARINDEX('212', TELPHONE , 1) = 1 THEN '1'+TELPHONE 
           WHEN CHARINDEX('1212', TELPHONE, 1) = 0 THEN '1212'+TELPHONE        
         ELSE TELPHONE 
         END     
    WHERE --(STATE LIKE '%UU%' OR STATE LIKE '%U&P%' OR STATE LIKE '%UTTER%') 
     --AND 
     LEN(TELPHONE) <= 10 AND TELPHONE<>''; 

Answer 2

這是因爲您的case與您不希望在第一個表達式中匹配的行匹配。重新排列你case讓您的212檢查至上，因爲這是一個積極的唯一匹配，並且如果不符合，才檢查陰性比賽上1212：

declare @t table (
       ID  int 
       ,TELEPHONE nvarchar(50) 
       ); 
insert into @t 
values (1923,'6276572'), 
     (1949,'2126670825'), 
     (2125,''), 
     (1926,'12126670825'); 

select Telephone 
     ,case when charindex('212',TELEPHONE,1) = 1 
       then '1'+TELEPHONE 
       when charindex('1212',TELEPHONE,1) = 0 
        and TELEPHONE <> '' 
       then '1212'+TELEPHONE 
       else TELEPHONE 
       end as TelephoneNew 
     ,charindex('212',TELEPHONE,1) as [212Match] 
     ,charindex('1212',TELEPHONE,1) as [1212Match] 
from @t 

輸出：

+-------------+--------------+----------+-----------+ 
| Telephone | TelephoneNew | 212Match | 1212Match | 
+-------------+--------------+----------+-----------+ 
|  6276572 | 12126276572 |  0 |   0 | 
| 2126670825 | 12126670825 |  1 |   0 | 
|    |    |  0 |   0 | 
| 12126670825 | 12126670825 |  2 |   1 | 
+-------------+--------------+----------+-----------+