PostgreSQL的:

UPDATE Sales_Import SI
SET AccountNumber = RAN.AccountNumber
FROM RetrieveAccountNumber RAN
WHERE RAN.LeadID = SI.LeadID; 

我相信一个带JOIN的UPDATE FROM会有帮助:

MS SQL

UPDATE
    Sales_Import
SET
    Sales_Import.AccountNumber = RAN.AccountNumber
FROM
    Sales_Import SI
INNER JOIN
    RetrieveAccountNumber RAN
ON 
    SI.LeadID = RAN.LeadID;

MySQL和MariaDB

UPDATE
    Sales_Import SI,
    RetrieveAccountNumber RAN
SET
    SI.AccountNumber = RAN.AccountNumber
WHERE
    SI.LeadID = RAN.LeadID;

Oracle 11 g

merge into Sales_Import
using RetrieveAccountNumber
on (Sales_Import.LeadId = RetrieveAccountNumber.LeadId)
when matched then update set Sales_Import.AccountNumber = RetrieveAccountNumber.AccountNumber;

似乎你正在使用MSSQL，然后，如果我没记错，它是这样做的:

UPDATE [Sales_Lead].[dbo].[Sales_Import] SET [AccountNumber] = 
RetrieveAccountNumber.AccountNumber 
FROM RetrieveAccountNumber 
WHERE [Sales_Lead].[dbo].[Sales_Import].LeadID = RetrieveAccountNumber.LeadID

MS Sql

UPDATE  c4 SET Price=cp.Price*p.FactorRate FROM TableNamea_A c4
inner join TableNamea_B p on c4.Calcid=p.calcid 
inner join TableNamea_A cp on c4.Calcid=cp.calcid 
WHERE c4..Name='MyName';

Oracle 11 g

        MERGE INTO  TableNamea_A u 
        using
        (
                SELECT c4.TableName_A_ID,(cp.Price*p.FactorRate) as CalcTot 
                FROM TableNamea_A c4
                inner join TableNamea_B p on c4.Calcid=p.calcid 
                inner join TableNamea_A cp on c4.Calcid=cp.calcid 
                WHERE p.Name='MyName' 
        )  rt
        on (u.TableNamea_A_ID=rt.TableNamea_B_ID)
        WHEN MATCHED THEN
        Update set Price=CalcTot  ;

对于SQL Server 2008 +使用MERGE而不是专有的更新…FROM语法有一些吸引力。

它不仅是标准SQL，因此更易于移植，而且在源端有多个连接行的情况下(因此在更新中可能使用多个不同的值)也会引发错误，而不是最终结果不确定。

MERGE INTO Sales_Import
   USING RetrieveAccountNumber
      ON Sales_Import.LeadID = RetrieveAccountNumber.LeadID
WHEN MATCHED THEN
   UPDATE 
      SET AccountNumber = RetrieveAccountNumber.AccountNumber;

然而，不幸的是，选择使用哪一种可能并不完全取决于首选的风格。SQL Server中MERGE的实现一直受到各种错误的困扰。Aaron Bertrand在这里整理了一份报告的清单。