在同一个表内更新:

  DECLARE @TB1 TABLE
    (
        No Int
        ,Name NVarchar(50)
        ,linkNo int
    )

    DECLARE @TB2 TABLE
    (
        No Int
        ,Name NVarchar(50)
        ,linkNo int
    )

    INSERT INTO @TB1 VALUES(1,'changed person data',  0);
    INSERT INTO @TB1 VALUES(2,'old linked data of person', 1);

INSERT INTO @TB2 SELECT * FROM @TB1 WHERE linkNo = 0


SELECT * FROM @TB1
SELECT * FROM @TB2


    UPDATE @TB1 
        SET Name = T2.Name
    FROM        @TB1 T1
    INNER JOIN  @TB2 T2 ON T2.No = T1.linkNo

    SELECT * FROM @TB1

下面是在SQL Server中对我有效的方法:

UPDATE [AspNetUsers] SET

[AspNetUsers].[OrganizationId] = [UserProfile].[OrganizationId],
[AspNetUsers].[Name] = [UserProfile].[Name]

FROM [AspNetUsers], [UserProfile]
WHERE [AspNetUsers].[Id] = [UserProfile].[Id];

更新表1 DPM set col1 = dpu。Col1 from table2 dpu其中dpm。Parameter_master_id = dpu.parameter_master_id;

总结其他答案，关于如何仅在“匹配存在”时使用来自另一个表的数据更新目标表，有4种变体

查询和子查询:

update si
set    si.AccountNumber = (
    select ran.AccountNumber 
    from   RetrieveAccountNumber ran
    where  si.LeadID = ran.LeadID
)
from Sales_Import si
where exists (select * from RetrieveAccountNumber ran where ran.LeadID = si.LeadID)

内连接:

update si
set si.AccountNumber = ran.AccountNumber
from Sales_Import si inner join RetrieveAccountNumber ran on si.LeadID = ran.LeadID

交叉连接:

update si
set si.AccountNumber = ran.AccountNumber
from Sales_Import si, RetrieveAccountNumber ran
where si.LeadID = ran.LeadID

走：

merge into Sales_Import si
using RetrieveAccountNumber ran on si.LeadID = ran.LeadID 
when matched then update set si.accountnumber = ran.accountnumber;

所有的变体都是更少的琐碎和可以理解的，我个人更喜欢“内部连接”选项。但其中任何一种都可以使用，开发者必须根据自己的需求选择“更好的选项”

从性能的角度来看，使用join的变体更可取:

试试这个:

UPDATE
    Table_A
SET
    Table_A.AccountNumber = Table_B.AccountNumber ,
FROM
    dbo.Sales_Import AS Table_A
    INNER JOIN dbo.RetrieveAccountNumber AS Table_B
        ON Table_A.LeadID = Table_B.LeadID 
WHERE
    Table_A.LeadID = Table_B.LeadID

MYSQL(这是我最喜欢的恢复所有特定列reasonId值的方法，基于主键id等价)

UPDATE `site` AS destination  
INNER JOIN `site_copy` AS backupOnTuesday 
      ON backupOnTuesday.`id` = destination.`id`
SET destdestination.`reasonId` = backupOnTuesday.`reasonId`