Question

假设我通过sql显式锁定行，如

BEGIN TRANSACTION
select * from bbajobs WITH (ROWLOCK, UPDLOCK) where JID=40970

然后我怎么能检测到JID为40970的行已被锁定？

我搜索谷歌并找到了一些解决方案，但那些不起作用。请帮我检测一下行是否锁定。感谢。

Answer 1

也许可以使用像sys.dm_tran_locks这样的系统视图，但是你通常会在页面上找到锁而不是单行，那么如果可行的话，找到特定行是否被锁定将是一件痛苦的事。 / p>

锁模型通常在应用程序中实现（如果您有独立的客户端程序，则在集中式应用程序服务器的内存中管理或在锁定表中管理）

Answer 2

使用 NOLOCK 和 READPAST 锁定提示。例如。假设您有一个表格，主键名为 Id

SELECT [Id] FROM [dbo].[TableName] WITH(NOLOCK)
WHERE [Id] NOT IN
(
    SELECT [Id] FROM [dbo].[TableName] WITH(READPAST)
)

Answer 3

You can get the list of non-committed transactions with the following query :

SELECT
    dm_tran_locks.request_session_id,
    dm_tran_locks.resource_database_id,
    DB_NAME(dm_tran_locks.resource_database_id) AS dbname,
    dm_tran_locks.resource_associated_entity_id,
    dm_tran_locks.resource_type,
    dm_tran_locks.resource_description,
    dm_tran_locks.resource_associated_entity_id,
    dm_tran_locks.request_mode,
    dm_tran_locks.request_status
FROM sys.dm_tran_locks 
WHERE resource_associated_entity_id > 0
AND resource_database_id = DB_ID();

Then it's possible to get data from the locked row with :

SELECT *
FROM [your_table]
WHERE %%lockres%% = '[insert dm_tran_locks.resource_description value]';

So, you can have the number of locks on your row for your example :

SELECT COUNT(1)
FROM sys.dm_tran_locks locks
INNER JOIN bbajobs
    ON bbajobs.%%lockres%% = locks.resource_description
WHERE
    resource_associated_entity_id > 0
AND
    -- Ensure the lock is on the same database
    resource_database_id = DB_ID()
AND
    -- Filter on row only
    resource_type = 'KEY'
AND
    -- Filter on request ID
    bbajobs.JID = 40970

如何检测sql server表中是否有行被锁定？

3 个答案: