從日期匹配的select語句更新多個值的表格

Question

我在更新表格時遇到問題，並且我確定它的表格非常簡單，但我在此處繞圈轉圈。

表「表1」的數據我想更新的格式如下：

[Month]     Figure 
---------------------------------- 
2010-05-01 00:00:00.000 1.0000 
2010-06-01 00:00:00.000 1.0000 
2010-07-01 00:00:00.000 1.0000 
2010-08-01 00:00:00.000 1.0000 

表「數據1」包含已更新的數據格式如下：

[Month]     Figure 
---------------------------------- 
2010-05-01 00:00:00.000 0.7212 
2010-08-01 00:00:00.000 1.2351 

的SQL我」 m使用和錯誤信息如下。

UPDATE t1 
SET t1.figure = (SELECT figure from data1) 
FROM table1 t1 JOIN data1 d1 
ON (t1.[month] = d1.[month]) 


Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression. 
The statement has been terminated. 

我需要一個while循環來遍歷每一行嗎？

祝最終結果是，如下所示：

[Month]     Figure 
---------------------------------- 
2010-05-01 00:00:00.000 0.7212 
2010-06-01 00:00:00.000 1.0000 
2010-07-01 00:00:00.000 1.0000 
2010-08-01 00:00:00.000 1.2351 

十分讚賞。

Answer 1

對此，您可以使用UPDATE FROM語法。

看看語法here和here。

FROM（table_source）

指定一個表，視圖或派生表源用於 更新操作

UPDATE t1 
SET  t1.figure = data1.figure 
FROM t1 
     INNER JOIN data1 ON data1.month = t1.month 

Answer 2

UPDATE t1 
SET t1.figure = data1.figure 
FROM table1 t1 JOIN data1 d1 
ON (t1.[month] = d1.[month]) 

Answer 3

SQL Server 2008中提供的標準：

MERGE INTO Table1 
USING data1 AS D1 
    ON Table1.my_Month = D1.my_Month 
WHEN MATCHED 
    THEN UPDATE 
      SET Figure = D1.Figure; 

Pre-SQL Server 2008：

UPDATE Table1 
    SET Figure = (
       SELECT D1.Figure 
        FROM data1 AS D1 
        WHERE Table1.my_Month = D1.my_Month 
       ) 
WHERE EXISTS (
       SELECT * 
       FROM data1 AS D1 
       WHERE Table1.my_Month = D1.my_Month 
      ); 

注意UPDATE..FROM語法是專有的，並且當目標行匹配多個源行可以產生不可預測的結果。