SQLException：处理 2 个不同的表时出现死锁错误

Question

我有死锁错误：

Transaction (Process ID 91) was deadlocked on lock resources with another process and has been chosen as the deadlock victim. Rerun the transaction.

图像死锁（https://i.stack.imgur.com/rDyxP.png）

Sp 91 是商店 Katzkin.dbo.ItemsAirBags_DX_IdItem:

delete ItemsAirBags
from ItemsAirBags  
where IdItem = @IdItem

Sp291 是商店 Katzkin.dbo.Items_TX_Description:

select *
from items  
where description = @description or left(description,5) = @description

我从 redgate 下载的完整 deadlock.xml：

 <deadlock>
  <victim-list>
    <victimProcess id="process366a0a5848" />
  </victim-list>
  <process-list>
    <process id="process366a0a5848" taskpriority="0" logused="6424" waitresource="KEY: 6:72057609466478592 (56dfc8bc1bd3)" waittime="134" ownerId="2620704196" transactionname="user_transaction" lasttranstarted="2021-01-25T10:48:53.610" XDES="0x4462dd4490" lockMode="U" schedulerid="11" kpid="14292" status="suspended" spid="91" sbid="0" ecid="0" priority="0" trancount="2" lastbatchstarted="2021-01-25T10:48:53.690" lastbatchcompleted="2021-01-25T10:48:53.687" lastattention="2021-01-25T08:32:04.567" clientapp=".Net SqlClient Data Provider" hostname="SQLSERVER" hostpid="17172" loginname="KatCa" isolationlevel="read committed (2)" xactid="2620704196" currentdb="6" lockTimeout="4294967295" clientoption1="671088672" clientoption2="128056">
      <executionStack>
        <frame procname="Katzkin.dbo.ItemsAirBags_DX_IdItem" line="2" stmtstart="136" stmtend="258" sqlhandle="0x030006006b1f922228e7730050ab000001000000000000000000000000000000000000000000000000000000">
delete ItemsAirBags from ItemsAirBags  
where IdItem = @IdIte    </frame>
      </executionStack>
      <inputbuf>
Proc [Database Id = 6 Object Id = 580001643]   </inputbuf>
    </process>
    <process id="process3dc4191468" taskpriority="0" logused="34720" waitresource="KEY: 6:72057609931325440 (b015ce3d2676)" waittime="62" ownerId="2620704065" transactionname="user_transaction" lasttranstarted="2021-01-25T10:48:53.500" XDES="0x3d45478490" lockMode="S" schedulerid="6" kpid="1500" status="suspended" spid="291" sbid="0" ecid="0" priority="0" trancount="1" lastbatchstarted="2021-01-25T10:48:53.760" lastbatchcompleted="2021-01-25T10:48:53.760" lastattention="2021-01-25T08:30:50.683" clientapp=".Net SqlClient Data Provider" hostname="SQLSERVER" hostpid="30552" loginname="KatCa" isolationlevel="read committed (2)" xactid="2620704065" currentdb="6" lockTimeout="4294967295" clientoption1="671088672" clientoption2="128056">
      <executionStack>
        <frame procname="Katzkin.dbo.Items_TX_Description" line="4" stmtstart="172" stmtend="348" sqlhandle="0x030006008513045381f88c002da3000001000000000000000000000000000000000000000000000000000000">
Select * from items  
where description=@description or left(description,5)=@descriptio    </frame>
      </executionStack>
      <inputbuf>
Proc [Database Id = 6 Object Id = 1392776069]   </inputbuf>
    </process>
  </process-list>
  <resource-list>
    <keylock hobtid="72057609466478592" dbid="6" objectname="Katzkin.dbo.ItemsAirBags" indexname="PK_ItemsAirBags" id="lock3ca39db480" mode="X" associatedObjectId="72057609466478592">
      <owner-list>
        <owner id="process3dc4191468" mode="X" />
      </owner-list>
      <waiter-list>
        <waiter id="process366a0a5848" mode="U" requestType="wait" />
      </waiter-list>
    </keylock>
    <keylock hobtid="72057609931325440" dbid="6" objectname="Katzkin.dbo.Items" indexname="PK_Items" id="lock3f52da2100" mode="X" associatedObjectId="72057609931325440">
      <owner-list>
        <owner id="process366a0a5848" mode="X" />
      </owner-list>
      <waiter-list>
        <waiter id="process3dc4191468" mode="S" requestType="wait" />
      </waiter-list>
    </keylock>
  </resource-list>
</deadlock>

我们在两个不同的表上但导致了死锁，我不明白原因以及如何解决它。关于如何解决这些问题有什么想法吗？

Answer 1

如死锁图所示，您有 2 个存储过程，它们都试图 update/access 相同的行，但出于某种原因，其中一个是 updating/accessing ItemsAirBags table 第一个和 Items table 第二个和另一个相反顺序的存储过程。这就是造成僵局的原因。如果您使两个存储过程 update/access 和 table 的顺序相同，您将消除死锁。

当您处理父子情况时，有时需要在更新父项和子项之前对计划更新的子行进行更新锁定。

您要确保始终 update/access 您的 table 顺序相同，因为这样第一个存储过程将阻塞第二个存储过程（这是您想要的）而不是死锁.

注意：这些存储过程中发生的事情一定比您的代码显示的要多，因为就目前而言，不会有死锁。进程 process3dc4191468 以某种方式在 ItemsAirBags 上有排他锁，这不是显示的 SQL 的一部分。

SQLException：处理 2 个不同的表时出现死锁错误

SQLException : Deadlock error when processing 2 different tables

sql-server

deadlock