SQL更新1個表中的多行

Question

我有個問題。 我正在使用MS SQL Server Management Studio。

我有一個包含很多翻譯的詞典表。 我需要將完整的描述從一個languageID復制到另一個languageID。

下面的例子。

LanguageID | Description
    2      | Some text
    2      | More text
    2      | Some more text
   10      | *needs to be replaced
   10      | *needs to be replaced
   10      | *needs to be replaced

結果必須是這樣的：

LanguageID | Description
    2      | Some text
    2      | More text
    2      | Some more text
   10      | Some text
   10      | More text
   10      | Some more text

LanguageID 2和10的描述必須完全相同。

我當前的查詢遇到錯誤：

update tblDictionary
set Description = (Select Description from tblDictionary where 
tblDictionary.LanguageID = 2)
where LanguageID = 10

消息512，級別16，狀態1，行1子查詢返回的值超過1。 當子查詢遵循=，！=，<，<=時，這是不允許的

，> =或將子查詢用作表達式時。 該語句已終止。

Answer 1

如果LanguageID 10的所有翻譯必須與languageID 2的翻譯完全相同，則可以輕松刪除ID 10的所有翻譯，然后重新插入。
像這樣

delete from tblDictionary where LanguageID = 10;

insert into tblDictionary (LanguageID, Description)
select 10, d.Description
from   tblDictionary d
where  d.LanguageID = 2

該方法還具有以下優勢：如果較少的記錄具有LanguageID = 10 ，則對於LanguageID = 2將在同一過程中對其進行更正。

如果tblDictionary中的列多於需要修改的插入語句

Answer 2

DECLARE @temp varchar(50)
DECLARE language_cursor CURSOR FOR  
SELECT Description FROM tblDictionary  
WHERE LanguageID = 2  
ORDER BY Description;  

OPEN language_cursor;  

-- Perform the first fetch.  
FETCH NEXT FROM language_cursor
into @temp;  

-- Check @@FETCH_STATUS to see if there are any more rows to fetch.  
WHILE @@FETCH_STATUS = 0  
BEGIN  
   update TOP (1) tblDictionary
   set Description = @temp
   where Description = ''
   and LanguageID = 10;  
   FETCH NEXT FROM language_cursor
   into @temp;
END  

CLOSE language_cursor;  
DEALLOCATE language_cursor;  

首先將所有languageID 10設置為空，然后循環遍歷languageID 2的所有描述以逐一更新為languageID 10，直到填充languageID10中的所有空白描述。

Answer 3

現在，如果您真的想要更新，即使我認為表的結構需要改進，類似的事情也應該起作用。

WITH l2 AS 
(SELECT *,  
 ROW_NUMBER() OVER(PARTITION BY LanguageId ORDER BY Description ASC) AS No FROM tblDictionary WHERE LanguageId=2),
l10 AS 
(SELECT *,  
 ROW_NUMBER() OVER(PARTITION BY LanguageId ORDER BY Description ASC) AS No FROM tblDictionary WHERE LanguageId=10)

UPDATE l10 SET Description = l2.Description 
FROM l10
INNER JOIN l2 ON l10.No = l2.No