TransactionIsolationLevel Enumeration
.NET Framework 3.5
Specifies the value of the TransactionAttribute.
Assembly: System.EnterpriseServices (in System.EnterpriseServices.dll)
| Member name | Description | |
|---|---|---|
| Any | The isolation level for the component is obtained from the calling component's isolation level. If this is the root component, the isolation level used is Serializable. | |
| ReadUncommitted | Shared locks are issued and no exclusive locks are honored. | |
| ReadCommitted | Shared locks are held while the data is being read to avoid reading modified data, but the data can be changed before the end of the transaction, resulting in non-repeatable reads or phantom data. | |
| RepeatableRead | Locks are placed on all data that is used in a query, preventing other users from updating the data. Prevents non-repeatable reads, but phantom rows are still possible. | |
| Serializable | Prevents updating or inserting until the transaction is complete. |
The following code example demonstrates the use of the TransactionIsolationLevel type.
using System; using System.EnterpriseServices; using System.Reflection; // References: // System.EnterpriseServices // An instance of this class will inherit its caller's transaction isolation // level if available. If not, it will use isolation level Serializable. [Transaction(Isolation=TransactionIsolationLevel.Any)] public class TransactionAttribute_IsolationAny : ServicedComponent { } // An instance of this class will read only committed data, but non-repeatable // reads and phantom rows are still possible. [Transaction(Isolation=TransactionIsolationLevel.ReadCommitted)] public class TransactionAttribute_IsolationReadCommitted : ServicedComponent { } // An instance of this class will read committed and uncommitted data, so dirty // reads, non-repeatable reads, and phantom rows are possible. [Transaction(Isolation=TransactionIsolationLevel.ReadUncommitted)] public class TransactionAttribute_IsolationReadUncommitted : ServicedComponent { } // An instance of this class will read only committed data and place shared // locks on the data, preventing other users from modifying it, but other users // can still insert rows into the data set, so phantom rows are still possible. [Transaction(Isolation=TransactionIsolationLevel.RepeatableRead)] public class TransactionAttribute_IsolationRepeatableRead : ServicedComponent { } // An instance of this class will read only committed data and place a range // lock on the data set, preventing other users from updating or inserting rows // into the data set until its transaction is complete. [Transaction(Isolation=TransactionIsolationLevel.Serializable)] public class TransactionAttribute_IsolationSerializable : ServicedComponent { }
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The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
