讀取認可 SQL Server SQL Server 可重複讀取 SQL Server 不支援 可序列化 SQL Server 不支援 讀取認可的快照集 SQL Server SQL Server 快照式 SQL Server SQL Server 範例 下列範例會設定工作階段的 TRANSACTION ISOLATION LEVEL。 SQL Server 會保留後來每個 Transact-SQL 陳述式的所有共用鎖定,直到交易完成為止。
SET TRANSACTION ISOLATION LEVEL (Transact-SQL) - SQL Server Save Add to Collections Add to Plan Share via Facebookx.comLinkedInEmail Print Article 09/04/2024 18 contributors Feedback In this article Syntax Arguments Remarks Examples See Also ...
For each Transact-SQL statement that follows, SQL Server holds all of the shared locks until the end of the transaction. SQL Copy USE AdventureWorks2022; GO SET TRANSACTION ISOLATION LEVEL REPEATABLE READ; GO BEGIN TRANSACTION; GO SELECT * FROM HumanResources.EmployeePayHistory; GO SELECT * ...
A transaction cannot be set to SNAPSHOT isolation level that started with another isolation level; doing so will cause the transaction to abort. If a transaction starts in the SNAPSHOT isolation level, you can change it to another isolation level and then back to SNAPSHOT. A transaction starts...
For each Transact-SQL statement that follows, SQL Server holds all of the shared locks until the end of the transaction. SQL Kopiér USE AdventureWorks2022; GO SET TRANSACTION ISOLATION LEVEL REPEATABLE READ; GO BEGIN TRANSACTION; GO SELECT * FROM HumanResources.EmployeePayHistory; GO SELECT *...
SQL Copiar USE AdventureWorks2022; GO SET TRANSACTION ISOLATION LEVEL REPEATABLE READ; GO BEGIN TRANSACTION; GO SELECT * FROM HumanResources.EmployeePayHistory; GO SELECT * FROM HumanResources.Department; GO COMMIT TRANSACTION; GO Consulte también...
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*...
(the default on SQL Server), the Database Engine uses shared locks to prevent other transactions from modifying rows while the current transaction is running a read operation. The shared locks also block the statement from reading rows modified by other transactions until the other transaction is ...
SET TRANSACTION ISOLATION LEVEL { READ COMMITTED | READ UNCOMMITTED | REPEATABLE READ | SERIALIZABLE } 参数 READ COMMITTED 指定在读取数据时控制共享锁以避免脏读,但数据可在事务结束前更改,从而产生不可重复读取或幻像数据。该选项是 SQL Server 的默认值。
Transact-SQL 语法约定 语法 SET TRANSACTION ISOLATION LEVEL { READ UNCOMMITTED | READ COMMITTED | REPEATABLE READ | SNAPSHOT | SERIALIZABLE } [ ; ] 参数 READ UNCOMMITTED 指定语句可以读取已由其他事务修改但尚未提交的行。 在READ UNCOMMITTED 级别运行的事务,不会发出共享锁来防止其他事务修改当前事务读取的...