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Removed custom TransactionManager. Closes #57.
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All transactions now fall through to MSDTC when used with TransactionScope. Use the LocalTransactionScope to use local transactions and bypass MSDTC.

IMPORTANT: This is a breaking change as of release 4.0.0.0. Connections are now NOT implicitly opened when any any Database.ConnectionController.Execute* function is called within a TransactionScope. Instead a ConnectionScope must also be used to call the Execute* statement. Previously, the connection would be implicitly opened if any Database.ConnectionController.Execute* functions was called within a TransactionScope using statement. Normal calls to DatabaseObject.Save or Database.ObjectSave are not affected, so only minor code changes (if any) should be required.
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@hisystems
hisystems committed May 5, 2012
1 parent 6792150 commit 85bc7fb
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Showing 3 changed files with 12 additions and 182 deletions.
5 changes: 1 addition & 4 deletions Database/ConnectionScope.vb
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Expand Up @@ -24,11 +24,8 @@ Public Class ConnectionScope

''' <summary>
''' Ensures that a new connection is opened.
''' If defined within a TransactionScope then the transaction is utilised
''' and object effectively does nothing.
''' If a connection is already opened then the already open connection is utilised.
''' </summary>
''' <param name="database"></param>
''' <remarks></remarks>
Public Sub New(database As Database)

If database Is Nothing Then
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187 changes: 10 additions & 177 deletions Database/Database.vb
View file
Expand Up @@ -1870,85 +1870,6 @@ Public Class Database

End Class

''' <summary>
''' Manages transactions when used with the System.Transactions.TransactionScope class.
''' </summary>
Private Class TransactionsManager
Implements System.Transactions.IEnlistmentNotification

Private pobjConnectionController As ConnectionController

Public Sub New(ByVal objConnectionController As ConnectionController)

If objConnectionController Is Nothing Then
Throw New ArgumentNullException
End If

pobjConnectionController = objConnectionController

End Sub

Friend Sub BeginTransaction(ByVal eIsolationLevel As System.Transactions.IsolationLevel)

pobjConnectionController.BeginTransaction(TranslateIsolationLevel(eIsolationLevel))

End Sub

''' <summary>
''' Translate the enum equivalents from the System.Transactions.IsolationLevel enum
''' to the System.Data.IsolationLevel enum.
''' </summary>
Private Function TranslateIsolationLevel(ByVal eIsolationLevel As System.Transactions.IsolationLevel) As System.Data.IsolationLevel

Select Case eIsolationLevel
Case System.Transactions.IsolationLevel.ReadCommitted
Return System.Data.IsolationLevel.ReadCommitted

Case System.Transactions.IsolationLevel.ReadUncommitted
Return System.Data.IsolationLevel.ReadUncommitted

Case System.Transactions.IsolationLevel.RepeatableRead
Return System.Data.IsolationLevel.RepeatableRead

Case System.Transactions.IsolationLevel.Serializable
Return System.Data.IsolationLevel.Serializable

Case System.Transactions.IsolationLevel.Snapshot
Return System.Data.IsolationLevel.Snapshot

Case System.Transactions.IsolationLevel.Unspecified
Return Data.IsolationLevel.Unspecified

Case Else
Throw New NotImplementedException(eIsolationLevel.ToString)
End Select

End Function

Private Sub Prepare(ByVal preparingEnlistment As System.Transactions.PreparingEnlistment) Implements System.Transactions.IEnlistmentNotification.Prepare

preparingEnlistment.Prepared()

End Sub

Private Sub Commit(ByVal enlistment As System.Transactions.Enlistment) Implements System.Transactions.IEnlistmentNotification.Commit

pobjConnectionController.CommitTransaction()

End Sub

Private Sub InDoubt(ByVal enlistment As System.Transactions.Enlistment) Implements System.Transactions.IEnlistmentNotification.InDoubt

End Sub

Private Sub Rollback(ByVal enlistment As System.Transactions.Enlistment) Implements System.Transactions.IEnlistmentNotification.Rollback

pobjConnectionController.RollbackTransaction()

End Sub

End Class

Public Class ConnectionController

''' <summary>
Expand Down Expand Up @@ -2014,40 +1935,7 @@ Public Class Database
<Obsolete("Use DatabaseObjects.ConnectionScope")>
Public Sub Start()

Dim objCurrentTransaction As Transaction = Transaction.Current

If objCurrentTransaction Is Nothing Then
' When not called from with a TransactionScope ensure a connection is open.
ConnectionStart()
Else
'Only create a new transaction when in a different TransactionScope
If pobjLastTransaction <> objCurrentTransaction Then
' When called from within a TransactionScope ensure a connection is open and a transaction started.
StartLocalTransaction(objCurrentTransaction)
pobjLastTransaction = objCurrentTransaction
End If
End If

End Sub

Private Sub StartLocalTransaction(ByVal objCurrentTransaction As System.Transactions.Transaction)

' When called from within a TransactionScope enlist a resource manager and begin the transaction
Dim objTransactionManager As TransactionsManager = New TransactionsManager(Me)

If peConnectionType = ConnectionType.MicrosoftAccess Then
'If this is the default isolation level
If objCurrentTransaction.IsolationLevel = System.Transactions.IsolationLevel.Serializable Then
'Isolation levels are not supported in Microsoft Access therefore ignore the isolation level specified
objTransactionManager.BeginTransaction(System.Transactions.IsolationLevel.Unspecified)
Else
Throw New Exceptions.DatabaseObjectsException("Isolation Level " & objCurrentTransaction.IsolationLevel.ToString & " is not supported for Microsoft Access")
End If
Else
objTransactionManager.BeginTransaction(objCurrentTransaction.IsolationLevel)
End If

objCurrentTransaction.EnlistVolatile(objTransactionManager, EnlistmentOptions.None)
ConnectionStart()

End Sub

Expand All @@ -2060,8 +1948,6 @@ Public Class Database
''' If not in transaction mode then the connection is closed.
''' Always call Finished when finished using the connection whether in
''' transaction mode or not as the library will close the connection if necessary.
''' If called within a TransactionScope() then the database transaction will be committed
''' at the end of the TransactionScope().
''' </summary>
''' <remarks>
''' This feature is particularly relevant when database records are locked
Expand All @@ -2075,29 +1961,7 @@ Public Class Database
<Obsolete("Use DatabaseObjects.ConnectionScope")>
Public Sub Finished()

Dim objCurrentTransaction As Transaction = Transaction.Current

If objCurrentTransaction Is Nothing Then
' When not called from with a TransactionScope the connection as finished.
ConnectionFinished()
Else
' When within a TransactionScope then the TransactionManager will commit and
' close the connection as necessary at the end of the TransactionScope's using statement.
End If

End Sub

''' <summary>
''' Allows the use of TransactionScope around a set of Execute, ExecuteNonQuery or ExecuteScalar
''' with out requiring an explicit call to .Start() as it should be implied from the fact that
''' the statements are wrapped in a TransactionScope() using statement.
''' </summary>
Private Sub StartIfInTransactionScope()

If pobjConnection.State = ConnectionState.Closed AndAlso Transaction.Current IsNot Nothing Then
' This will cause the transaction to start
Me.Start()
End If
ConnectionFinished()

End Sub

Expand Down Expand Up @@ -2204,17 +2068,12 @@ Public Class Database
''' Executes the SQL statement.
''' Returns Nothing/null if no record was selected, otherwise the first field from the
''' returned result.
''' ConnectionController.Start must be called prior to and
''' ConnectionController.Finished afterwards or the statement be wrapped in a TransactionScope().
''' Otherwise the connection will not be correctly closed.
''' If wrapped in a TransactionScope call then Start is implicitly called if it has
''' not been called previously with the transaction scope.
''' ConnectionController.Start must be called prior to and ConnectionController.Finished afterwards,
''' otherwise the connection will not be correctly closed.
''' </summary>
''' --------------------------------------------------------------------------------
Public Function ExecuteScalar(ByVal objSQLStatement As SQL.ISQLStatement) As Object

StartIfInTransactionScope()

Dim objDataReader As IDataReader = ExecuteInternal(pobjConnection, objSQLStatement)

If objDataReader.Read() Then
Expand Down Expand Up @@ -2252,79 +2111,54 @@ Public Class Database
''' --------------------------------------------------------------------------------
''' <summary>
''' Executes the SQL statement.
''' ConnectionController.Start must be called prior to and
''' ConnectionController.Finished afterwards or the statement be wrapped in a TransactionScope().
''' Otherwise the connection will not be correctly closed.
''' If wrapped in a TransactionScope call then Start is implicitly called if it has
''' not been called previously with the transaction scope.
''' ConnectionController.Start must be called prior to and ConnectionController.Finished afterwards.
''' </summary>
''' --------------------------------------------------------------------------------
Public Function Execute(ByVal objSQLStatement As SQL.ISQLStatement) As IDataReader

StartIfInTransactionScope()

Return ExecuteInternal(pobjConnection, objSQLStatement)

End Function

''' --------------------------------------------------------------------------------
''' <summary>
''' Executes the SQL statements.
''' ConnectionController.Start must be called prior to and
''' ConnectionController.Finished afterwards or the statement be wrapped in a TransactionScope().
''' Otherwise the connection will not be correctly closed.
''' If wrapped in a TransactionScope call then Start is implicitly called if it has
''' not been called previously with the transaction scope.
''' ConnectionController.Start must be called prior to and ConnectionController.Finished afterwards.
''' </summary>
''' --------------------------------------------------------------------------------
Public Function Execute(ByVal objSQLStatements As SQL.ISQLStatement()) As IDataReader

StartIfInTransactionScope()

Return ExecuteInternal(pobjConnection, New SQL.SQLStatements(objSQLStatements))

End Function

''' --------------------------------------------------------------------------------
''' <summary>
''' Executes the SQL statement.
''' ConnectionController.Start must be called prior to and
''' ConnectionController.Finished afterwards or the statement be wrapped in a TransactionScope().
''' Otherwise the connection will not be correctly closed.
''' If wrapped in a TransactionScope call then Start is implicitly called if it has
''' not been called previously with the transaction scope.
''' ConnectionController.Start must be called prior to and ConnectionController.Finished afterwards.
''' </summary>
''' --------------------------------------------------------------------------------
Public Function ExecuteNonQuery(ByVal objSQLStatement As SQL.ISQLStatement) As Integer

StartIfInTransactionScope()

Return ExecuteNonQueryInternal(pobjConnection, objSQLStatement)

End Function

''' --------------------------------------------------------------------------------
''' <summary>
''' Executes the SQL statements.
''' ConnectionController.Start must be called prior to and
''' ConnectionController.Finished afterwards or the statement be wrapped in a TransactionScope().
''' Otherwise the connection will not be correctly closed.
''' If wrapped in a TransactionScope call then Start is implicitly called if it has
''' not been called previously with the transaction scope.
''' ConnectionController.Start must be called prior to and ConnectionController.Finished afterwards.
''' </summary>
''' --------------------------------------------------------------------------------
Public Function ExecuteNonQuery(ByVal objSQLStatements As SQL.ISQLStatement()) As Integer

StartIfInTransactionScope()

Return ExecuteNonQueryInternal(pobjConnection, New SQL.SQLStatements(objSQLStatements))

End Function

''' --------------------------------------------------------------------------------
''' <summary>
''' Executes an SQL statement on a new connection from the connection pool or
''' if in transaction mode the current connection.
''' Executes an SQL statement on a new connection from the connection pool.
''' ConnectionController.Start or ConnectionController.Finished do not have to be called.
''' </summary>
''' --------------------------------------------------------------------------------
Expand All @@ -2339,8 +2173,7 @@ Public Class Database

''' --------------------------------------------------------------------------------
''' <summary>
''' Executes the SQL statements on a new connection from the connection pool or
''' if in transaction mode the current connection.
''' Executes the SQL statements on a new connection from the connection pool.
''' ConnectionController.Start or ConnectionController.Finished do not have to be called.
''' </summary>
''' --------------------------------------------------------------------------------
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2 changes: 1 addition & 1 deletion Database/MicrosoftSQLServerDatabase.vb
View file
Expand Up @@ -141,7 +141,7 @@ Public Class MicrosoftSQLServerDatabase

Private Shared Function ConnectionStringRoot(ByVal strDataSource As String, ByVal strDatabaseName As String) As String

Return "Provider=SQLOLEDB;Data Source=" & strDataSource & ";" & "Database=" & strDatabaseName & ";OLE DB Services=-3;"
Return "Provider=SQLOLEDB;Data Source=" & strDataSource & ";" & "Database=" & strDatabaseName & ";"

End Function

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