如何找到当前的交易水平？

Question

如何在 SQL Server 上找到当前数据库的事务级别？

Answer 1

运行这个：

SELECT CASE transaction_isolation_level 
WHEN 0 THEN 'Unspecified' 
WHEN 1 THEN 'ReadUncommitted' 
WHEN 2 THEN 'ReadCommitted' 
WHEN 3 THEN 'Repeatable' 
WHEN 4 THEN 'Serializable' 
WHEN 5 THEN 'Snapshot' END AS TRANSACTION_ISOLATION_LEVEL 
FROM sys.dm_exec_sessions 
where session_id = @@SPID

docs.microsoft.com reference for the constant values.

Answer 2

只要运行DBCC useroptions，你就会得到这样的结果：

Set Option                  Value
--------------------------- --------------
textsize                    2147483647
language                    us_english
dateformat                  mdy
datefirst                   7
lock_timeout                -1
quoted_identifier           SET
arithabort                  SET
ansi_null_dflt_on           SET
ansi_warnings               SET
ansi_padding                SET
ansi_nulls                  SET
concat_null_yields_null     SET
isolation level             read committed

Answer 3

SELECT CASE  
          WHEN transaction_isolation_level = 1 
             THEN 'READ UNCOMMITTED' 
          WHEN transaction_isolation_level = 2 
               AND is_read_committed_snapshot_on = 1 
             THEN 'READ COMMITTED SNAPSHOT' 
          WHEN transaction_isolation_level = 2 
               AND is_read_committed_snapshot_on = 0 THEN 'READ COMMITTED' 
          WHEN transaction_isolation_level = 3 
             THEN 'REPEATABLE READ' 
          WHEN transaction_isolation_level = 4 
             THEN 'SERIALIZABLE' 
          WHEN transaction_isolation_level = 5 
             THEN 'SNAPSHOT' 
          ELSE NULL
       END AS TRANSACTION_ISOLATION_LEVEL 
FROM   sys.dm_exec_sessions AS s
       CROSS JOIN sys.databases AS d
WHERE  session_id = @@SPID
  AND  d.database_id = DB_ID();

Answer 4

DECLARE   @UserOptions TABLE(SetOption varchar(100), Value varchar(100))
DECLARE   @IsolationLevel varchar(100)

INSERT    @UserOptions
EXEC('DBCC USEROPTIONS WITH NO_INFOMSGS')

SELECT    @IsolationLevel = Value
FROM      @UserOptions
WHERE     SetOption = 'isolation level'

-- Do whatever you want with the variable here...  
PRINT     @IsolationLevel

Answer 5

如果您谈论的是当前事务嵌套级别，那么您将使用@@TRANCOUNT。

如果您在谈论事务隔离级别，请使用DBCC USEROPTIONS 并查找隔离级别的选项。如果未设置，则已提交读取。

Answer 6

SELECT CASE  
    WHEN transaction_isolation_level = 0 THEN 'Unspecified' 
    WHEN transaction_isolation_level = 1 THEN 'Read Uncommitted' 
    WHEN transaction_isolation_level = 2 AND d.snapshot_isolation_state_desc = 'OFF' THEN 'Read Committed' 
    WHEN transaction_isolation_level = 2 AND d.snapshot_isolation_state_desc = 'ON' AND d.is_read_committed_snapshot_on = 1 THEN 'Snapshot Read Committed'  
    WHEN transaction_isolation_level = 2 AND d.snapshot_isolation_state_desc = 'ON' AND d.is_read_committed_snapshot_on = 0 THEN 'Snapshot'  
    WHEN transaction_isolation_level = 3 THEN 'Repeatable Read' 
    WHEN transaction_isolation_level = 4 THEN 'Serializable' END AS TRANSACTION_ISOLATION_LEVEL,
    d.is_read_committed_snapshot_on,
    d.snapshot_isolation_state_desc
FROM sys.dm_exec_sessions 
       CROSS JOIN sys.databases AS d
where session_id = @@SPID
  AND  d.database_id = DB_ID();