我想在一个表中更新一个列，在其他表上进行连接，例如:
UPDATE table1 a
INNER JOIN table2 b ON a.commonfield = b.[common field]
SET a.CalculatedColumn= b.[Calculated Column]
WHERE
b.[common field]= a.commonfield
AND a.BatchNO = '110'
但它在抱怨:
警报170,15层，状态1,2号线 第2行:'a'附近的语法错误。
这里出了什么问题?
当前回答
MERGE table1 T
USING table2 S
ON T.CommonField = S."Common Field"
AND T.BatchNo = '110'
WHEN MATCHED THEN
UPDATE
SET CalculatedColumn = S."Calculated Column";
其他回答
Try:
UPDATE table1
SET CalculatedColumn = ( SELECT [Calculated Column]
FROM table2
WHERE table1.commonfield = [common field])
WHERE BatchNO = '110'
我也有同样的问题。而且你不需要添加一个物理列。因为现在你必须维护它。 你能做的就是在select查询中添加一个泛型列:
EX:
select tb1.col1, tb1.col2, tb1.col3 ,
(
select 'Match' from table2 as tbl2
where tbl1.col1 = tbl2.col1 and tab1.col2 = tbl2.col2
)
from myTable as tbl1
试着这样做:
UPDATE a
SET a.CalculatedColumn= b.[Calculated Column]
FROM table1 a INNER JOIN table2 b ON a.commonfield = b.[common field]
WHERE a.BatchNO = '110'
另一种方法是使用MERGE
;WITH cteTable1(CalculatedColumn, CommonField)
AS
(
select CalculatedColumn, CommonField from Table1 Where BatchNo = '110'
)
MERGE cteTable1 AS target
USING (select "Calculated Column", "Common Field" FROM dbo.Table2) AS source ("Calculated Column", "Common Field")
ON (target.CommonField = source."Common Field")
WHEN MATCHED THEN
UPDATE SET target.CalculatedColumn = source."Calculated Column";
-Merge是SQL标准的一部分
-我也很确定内部连接更新是不确定的。 类似的问题，答案是这样说的 http://ask.sqlservercentral.com/questions/19089/updating-two-tables-using-single-query.html
我发现将UPDATE转换为SELECT很有用，可以在更新之前获得我想要更新的作为测试的行。如果我能准确地选择我想要的行，我就可以更新我想要更新的行。
DECLARE @expense_report_id AS INT
SET @expense_report_id = 1027
--UPDATE expense_report_detail_distribution
--SET service_bill_id = 9
SELECT *
FROM expense_report_detail_distribution erdd
INNER JOIN expense_report_detail erd
INNER JOIN expense_report er
ON er.expense_report_id = erd.expense_report_id
ON erdd.expense_report_detail_id = erd.expense_report_detail_id
WHERE er.expense_report_id = @expense_report_id
