Error-Events.md

keywords: Any Error, Locked Row, Duplicate Index, Constraint failure, Trigger failure, Record has been updated, Record changed by antoher user, Insert/Update/Delete failure, Unmapped errors, As strategy, Abort Task, Rollback and restart, Auto retry, User retry, Ignore, Task, Subtree, AllErrors, LockedRow, DuplicateIndex, ConstraintFailed, TriggerFailed, RowWasChangedSinceLoaded, UpdatedRowWasChangedSinceLoaded, DataChangedFailed, UnknownErrr, Deadlock, FailedToInitializeEntity, InvalidSQLStatement, NullInOnlyOnePartOfDateTimePair, ReadOnlyEntityUpdate, RowDoesNotExist, TransactionRolledBack, Default, AbortTask, RollbackAndRecover, Retry, Ignore, AbortAllTasks, Rollback, Throw, CurrentTaskOnly, CurrentContext, UnhandledCustomCommandInModule, DatabaseErrorType, DatabaseErrorHandlingStrategy, HandlerScope

In Magic you have the option to trap database errors by an error event in order to handle the eror in a different way or register the error. In Firefly these are called database error handlers. See also: http://doc.fireflymigration.com/database-error-handling-with-transaction-stack-and-scope.html for more information on how you can adjust the error handling in Firefly yourself.

Add the following 'using' to your program (if not already present):

using Firefly.Box.Data.DataProvider;

And if also not already present add:

	InitializeHandlers();

Sample code on how to add a error handler:

void InitializeHandlers()
{
    Handlers.AddDatabaseErrorHandler(DatabaseErrorType.RowWasChangedSinceLoaded, HandlerScope.CurrentContext).Invokes += e =>
    #region
    {
        e.HandlingStrategy = DatabaseErrorHandlingStrategy.Ignore;
        Common.ShowDatabaseErrorMessage = false;
        e.Handled = true;
    };
    #endregion
}

Firefly error handlers

The error trapping options are (Magic compared to Firefly):

DatabaseErrorType

#	Error:	Val	DatabaseErrorType	Remark
1	Any Error	0	AllErrors	Represents any and all errors
2	Locked Row	3	LockedRow	An attempt to lock a row failed because the row is already locked by another session
3	Duplicate index	2	DuplicateIndex	Occurs when values are updated or inserted to the database, and a unique contraint in the database is violated
4	Constraint failure	5	ConstraintFailed
5	Trigger failure	10	TriggerFailed
6	Record has been updated	7	RowWasChangedSinceLoaded
7	Record changed by another user	14	UpdatedRowWasChangedSinceLoaded
8	Insert/Update/Delete failure	4	DataChangedFailed	An attempt to perform update, insert or delete failed for an unspecified reason
9	Unmapped errors	1	UnknownError	An error that is not specificly defined
-		8	Deadlock
-		12	FailedToInitializeEntity
-		13	InvalidSQLStatement
-		11	NullInOnlyOnePartOfDateTimePair
-		9	ReadOnlyEntityUpdate
-		6	RowDoesNotExist	<This handler is automatically added during migration if 'Unmapped error' is used in Magic>
-		15	TransactionRolledBack

DatabaseErrorHandlingStrategy

Dir:	Val	DatabaseErrorHandlingStrategy	Remark
As strategy	1	Default	The default behaviour of the error
Abort Task	7	AbortTask	The current task will close
Rollback and restart	3	RollbackAndRecover	The transaction will be rolled back, and the task that started the transaction will try to recover according to the UIController.OnDatabaseErrorRetry property
Auto retry	2	Retry	The operation will be retried
User retry	1	Default
Ignore	0	Ignore	Ignore the error, and try to process
-	6	AbortAllTasks	All open tasks will be closed
-	4	Rollback	The transaction will be rolled back, and the task that started the transaction will be terminated
-	5	Throw	The exception will be thrown and the transaction will be rolled back

HandlerScope

Scope:	Val	HandlerScope	Remark
Task	0	CurrentTaskOnly	Only commands invoked by the currrent task are handled
Subtree	1	CurrentContext (=Default)	Any comand invoked by the current task, or commands that were invoked by tasks that were called by the current task
-	2	UnhandledCustomCommandInModule	Relevant for handlers that reside in a task that inherits from ModuleController

Contributor: Harry Kleinsmit.