控制SQL Server 連線發出之 Transact-SQL 陳述式的鎖定和資料列版本設定行為。Transact-SQL 語法慣例Syntaxsyntaxsql 複製 -- Syntax for SQL Server and Azure SQL Database SET TRANSACTION ISOLATION LEVEL { READ UNCOMMITTED | READ COMMITTED | REPEATABLE READ | SNAPSHOT | SERIALIZABLE } ...
SQL Server does not guarantee that lock hints will be honored in queries that access metadata through catalog views, compatibility views, information schema views, metadata-emitting built-in functions.Internally, the SQL Server Database Engine only honors the READ COMMITTED isolation level for metadata...
In SQL Server, you can also minimize locking contention while protecting transactions from dirty reads of uncommitted data modifications using either: The READ COMMITTED isolation level with the READ_COMMITTED_SNAPSHOT database option set to ON. ...
对于每个后续 Transact-SQL 语句,SQL Server 将所有共享锁一直保持到事务结束为止。 复制 USE AdventureWorks; GO SET TRANSACTION ISOLATION LEVEL REPEATABLE READ; GO BEGIN TRANSACTION; GO SELECT * FROM HumanResources.EmployeePayHistory; GO SELECT * FROM HumanResources.Department; GO COMMIT TRANSACTION; GO...
如果我们不允许这种事情发生, 那么可以 set Isolation Level 为 Read Committed 或者更高 Level. 设定后, 遇到读脏数据它就会先等待. 等到对方事务提交后才会读取可靠的值. 注: SQL 默认的 Level 就是 Read Committed. 所以通常我们不需要设置这个的, 反之如果我们不希望等待则可以设定 Level 为 Read Uncommitted,...
快照SQL ServerSQL Server 示例 以下示例为会话设置了TRANSACTION ISOLATION LEVEL。 对于每个后续 Transact-SQL 语句,SQL Server 将所有共享锁一直保持到事务结束为止。 SQL USEAdventureWorks2022; GOSETTRANSACTIONISOLATIONLEVELREPEATABLEREAD; GOBEGINTRANSACTION; GOSELECT*FROMHumanResources.EmployeePayHistory; GOSELECT*...
快照SQL ServerSQL Server 示例 以下示例为会话设置了TRANSACTION ISOLATION LEVEL。 对于每个后续 Transact-SQL 语句,SQL Server 将所有共享锁一直保持到事务结束为止。 SQL USEAdventureWorks2022; GOSETTRANSACTIONISOLATIONLEVELREPEATABLEREAD; GOBEGINTRANSACTION; GOSELECT*FROMHumanResources.EmployeePayHistory; GOSELECT*...
SQL Server does not guarantee that lock hints will be honored in queries that access metadata through catalog views, compatibility views, information schema views, metadata-emitting built-in functions.Internally, the SQL Server Database Engine only honors the READ COMMITTED isolation level for metadata...
In SQL Server, you can also minimize locking contention while protecting transactions from dirty reads of uncommitted data modifications using either: The READ COMMITTED isolation level with the READ_COMMITTED_SNAPSHOT database option set to ON. The SNAPSHOT isolation level. For more information about...
关于Sql Server 事务隔离级别,百度百科是这样描述的 隔离级别:一个事务必须与由其他事务进行的资源或数据更改相隔离的程度。隔离级别从允许的并发副作用(例如,脏读或虚拟读取)的角度进行描述。 隔离级别共5种: read uncommitted | 0 未提交读 read committed | 1 已提交读 ...