Consultingwerk.OERA.DataAccess - SmartComponent Library

Namespace:

Consultingwerk.OERA

Class

DataAccess

Parent classes:

Progress.Lang.Object

Consultingwerk.OERA.DataAccess

Inherits:

Progress.Lang.Object

Implements:

Consultingwerk.OERA.IDataAccess, Consultingwerk.OERA.IDataAccessCanFind, Consultingwerk.OERA.IDataAccessCountRecords, Consultingwerk.OERA.Query.IDSQueryStringSource

Inherited by:

ABSTRACT

File:	DataAccess
Purpose:	Abstract base class for OERA Data Access objects
Author(s):	Mike Fechner / Consultingwerk Ltd.
Created:	Wed Feb 24 22:19:03 CET 2010

Navigate to: Methods | Constructors | Events | Properties

Top Method Summary

Options	Name	Purpose
#	AssignKeyFieldValues (handle)	Invoked by DataAccess:CommitChanges within the database transaction to optionally assign key field values for new records
#	LOGICAL AttachDataSource (handle, handle, character)	Attaches a data-source object to a temp-table buffer in a ProDataSet object
#	LOGICAL AttachDataSource (handle, handle, character, character)	Attaches a data-source object to a temp-table buffer in a ProDataSet object
#	LOGICAL AttachDataSource (handle, handle, character, character, character)	Attaches a data-source object to a temp-table buffer in a ProDataSet object
#	LOGICAL AttachDataSource (handle, IBufferDataSource)	Attaches a data-source object generated by an BufferDataSource instance to a temp-table buffer in a ProDataSet object
#	LOGICAL AttachDataSource (handle, IBufferDataSource, character)	Attaches a data-source object generated by an BufferDataSource instance to a temp-table buffer in a ProDataSet object
# A	AttachDataSources ()	Attaches the DATA-SOURCE objects to the ProDataset Buffers
#	CHARACTER BuildDataSourceQueryString (handle, IFetchDataRequest, character)	Returns the Query String to be used for the DATA-SOURCE of a ProDataset member buffer
+	CanFind (CanFindParameter)	Returns a TRUE value if a record is found that meets the specified FIND criteria; otherwise it returns FALSE. CAN-FIND does not make the record available to the Business Entity or it's caller.
#	CommitChanges (handle)	This method is called from SaveChanges in the DA to do the actual database commit and any transaction-related validation logic for a buffer.
+	CountResultRecords (ICountRecordsRequest)	Counts the number of result records in the data source query
#	LOGICAL DatasetBufferFill (handle, IFetchDataRequest)	Invokes the FILL method of a ProDataset member buffer
#	LOGICAL DatasetFill (handle, IFetchDataRequest)	Invokes the ProDataset FILL method
# A	DefineReadEvents ()	TO-DO: Subscribe to ProDataset Event Handlers using SET-CALLBACK as needed
# A	DetachDataSources ()	Detaches the DATA-SOURCE objects to the ProDataset Buffers
#	CHARACTER ExpandTables (character)	Expands the FetchDataRequest:Tables parameter, in case it contains the * wild-card character
+	FetchData (IFetchDataRequest)	Fetch data from the data source
+	FetchDataByKeyTable (IFetchDataByKeyTableParameter)	Allows retrieve multiple DB records from a Business Entity based on a temp-table with key values
-	FetchDataInternal (IFetchDataRequest)	Fetch data from the data source
#	ROWID FindRecord (character, handle, character, integer, integer)	Finds a record in the data source query and returns the ROWID ARRAY (used as RESTART-ROWID in FetchData)
#	Consultingwerk.OERA.FindRecordResult FindRecord2 (character, handle, character, integer, integer)	Finds a record in the data source query and returns the ROWID ARRAY (used as RESTART-ROWID in FetchData)
#	FindSourceBuffer (handle, logical)	Locates the matching record in the first source buffer of the given Dataset Buffer
#	HandleRecordLockedError (handle, SysError)	Handles a record locked error invoked during the SAVE-ROW-CHANGES method
#	HANDLE InsertToDataSourceQuery (handle, IFetchDataRequest, character)	Creates a new Query to be used as a DATA-SOURCE for a ProDataset member buffer
#	InvokeCommitChangesCallback (CommitCallbackTypeEnum, handle)	Invokes a CommitChangesCallback
#	Consultingwerk.OERA.IDSQueryString NewDSQueryString (character, character)	Factory method for the DSQueryString objects
#	Consultingwerk.OERA.IDSQueryString NewDSQueryString (character, character, logical)	Factory method for the DSQueryString objects
#	Consultingwerk.OERA.IDSQueryString NewDSQueryStringForKeyValueTable (character, character, logical, IFetchDataByKeyTableParameter, character)	Factory method for the DSQueryStringForKeyValueTable objects
#	Consultingwerk.IQueryRowIdentifier NewQueryRowIdentifier ()	Overridable factory method to create an instance of the IQueryRowIdentifier class
#	OnAfterSaveChanges (EventArgs)	Raises the AfterSaveChanges
#	OnAfterSavingRowChanges (SaveRowChangesEventArgs)	Raises the AfterSavingRowChanges event
#	OnBeforeSaveChanges (EventArgs)	Raises the BeforeSaveChanges
#	OnBeforeSavingRowChanges (SaveRowChangesEventArgs)	Raises the BeforeSavingRowChanges event
#	OnHandleCommitError (HandleCommitErrorEventArgs)	Raises the HandleCommitError
#	OnHandleCommitSysError (HandleCommitErrorEventArgs)	Raises the HandleCommitSysError
+	CHARACTER ParentRelationSourceQueryString (handle)	Returns the query string matching the DATA-RELATION field pairs referencing the source fields on the parent table
+	RepositionBackwards (handle, integer)	Reposition the given query backwards by the given number of records
#	ROWID RepositionBackwards (handle, rowid[], integer)	Evaluates the ROWID from which the ProDataset FILL operation needs to start on a backwards fill operation
#	SaveBuffer (handle)	Called from saveChanges to process changes for a single DataSet temp-table buffer.
+	SaveChanges ()	Save changes to physical storage
#	SaveRowChanges (handle)	Overridable method that executes SAVE-ROW-CHANGES on the before buffer
#	SetDatasetBufferCallback (handle, character, character)	Sets's a ProDataset Buffer Callback-Method (BEFORE-FILL, AFTER-FILL, BEFORE-ROW-FILL, ...)
#	SetDatasetBufferCallback (handle, character, character, Object)	Sets's a ProDataset Buffer Callback-Method (BEFORE-FILL, AFTER-FILL, BEFORE-ROW-FILL, ...)
#	SetDatasetCallback (character, character)	Sets's a ProDataset Callback-Method (BEFORE-FILL, AFTER-FILL)
#	SetDatasetCallback (character, character, Object)	Sets's a ProDataset Callback-Method (BEFORE-FILL, AFTER-FILL)
#	Consultingwerk.IQueryRowIdentifier SkipRecords (integer, handle)	Returns the Query Row Identifier (ROWID) to be used when navigating that DATA-SOURCE query based on the Skip argument of the FetchDataRequest
+ A	CHARACTER SourceColumn (character, character)	Returns the database field name matching a temp-table field name contained in a consumers query string (query string vs. temp-table definition)
+ A	CHARACTER SourceDefaultQuery (character)	Returns the base query string used to retrieve data for the temp tables. This query string will be appended by the query provided by the consumer (FetchDataRequest object).
#	SuggestDataSourceIndex (handle, character)	Method allows enforcing specific indexes when populating child record of a data-relation. When the parent buffer and the child buffer are FILL'ed during the ProDataset:FILL() operation, we ensure the given index

Top Constructor Summary

	Options	Name	Purpose
	+	DataAccess (handle)	Constructor of the DataAccess objects

Top Event Summary

Options	Name	Purpose
+	AfterSaveChanges (Object, EventArgs)	Raised at the end of SaveChanges - within the database transaction block
+	AfterSavingRowChanges (Object, SaveRowChangesEventArgs)	Event raised after the execution of the SAVE-ROW-CHANGES method for an individul record in the DataAccessObject
+	BeforeSaveChanges (Object, EventArgs)	Raised at the beginning of SaveChanges - within the database transaction block
+	BeforeSavingRowChanges (Object, SaveRowChangesEventArgs)	Event raised before the execution of the SAVE-ROW-CHANGES method for an individul record in the DataAccessObject
+	HandleCommitError (Object, HandleCommitErrorEventArgs)	Raised to allow custom handling of AppError's (Application errors, e.g. from DB triggers) raised while performing the SaveRowChanges method
+	HandleCommitSysError (Object, HandleCommitErrorEventArgs)	Raised to allow custom handling of SysError's (Progress runtime errors) raised while performing the SaveRowChanges method

Top Property Summary

Options	Name	Purpose
#	Consultingwerk.Framework.Collections.CharacterDictionary AssignSkipDictionary	Gets the reference to a CharacterDictionary with an entry per buffer (after-buffer name) as the key and the the skip-list of the SAVE-ROW-CHANGES method used as the value
+	CHARACTER AssignSkipList	Gets and sets the skip-list of the SAVE-ROW-CHANGES method used as the skip-list of the SAVE-ROW-CHANGES method used in CommitChanges method
+	CHARACTER CUSTOM_LOG_ENTRY	Gets the custom log file entry used by the DataAccess class
+	HANDLE DatasetHandle	Gets the reference to the Dataset handle used by this Data Access object
#	LOGICAL DataSourcesAttached	Returns if the DataSources are currently attached
#	Consultingwerk.OERA.IFetchDataRequest FetchDataRequest	Returns the reference to the current IFetchDataRequest instance
+	LOGICAL FilterUsingInnerJoin	Instructs the Query-Builder in method BuildQueryString to remove an eventually present OUTER-JOIN keyword from the source default query when filtering on a ceratin table.
+	LOGICAL ForceApplyQueryOnChildTables	Allows to force applying the Source Default Query to child tables even when no filter expression was provided by the consumer
+	LOGICAL LogFetchDataDetails	Allows to turn on and off the logging of details of the FetchData method execution
#	LOGICAL PrepareJoinedChildTableQueries	Gets and sets if the Data Access class should prepare the query on joined child tables during FetchData
#	Consultingwerk.OERA.QueryPurposeEnum QueryPurpose	Returns the current purpose of the SourceDefaultQuery callback
+	Consultingwerk.OERA.Enum.RequestTypeEnum RequestType	Returns the type of the current request (FetchData/SaveChanges)
#	LOGICAL ThrowErrorsOnFillFailed	Gets and sets if errors (negative return-value) during the ProDataset FILL() method should cause an error thrown by the DataAccess class

Method Detail

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PROTECTED AssignKeyFieldValues (handle)

Purpose:	Invoked by DataAccess:CommitChanges within the database transaction
	to optionally assign key field values for new records
Notes:	Provides a hook to assign key fields for new records before the
	changes (create) are written to the database. The default implementation
	of this method does nothing. Override this method to implement specific
	code

Parameters:
phBeforeBuffer	HANDLE
	The handle of the before buffer

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PROTECTED LOGICAL AttachDataSource (handle, handle, character)

Purpose:	Attaches a data-source object to a temp-table buffer in a ProDataSet
	object
Notes:	Filters out any white space character from the field lists to allow
	for human readable source code in the DataAccess classes
	AttachDataSources method

Parameters:
phDatasetBuffer	HANDLE
	The handle of the ProDataset Buffer
phDataSource	HANDLE
	The handle of the DATA-SOURCE object
pcPairsList	CHARACTER
	pairs-list An optional character expression that evaluates to a comma-delimited list of field name pairs that specify a mapping between different field names in the data-source object buffer and the ProDataSet temp-table buffer
Returns	LOGICAL
	Logical return value of the ATTACH-DATA-SOURCE method

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PROTECTED LOGICAL AttachDataSource (handle, handle, character, character)

Purpose:	Attaches a data-source object to a temp-table buffer in a ProDataSet
	object
Notes:	Filters out any white space character from the field lists to allow
	for human readable source code in the DataAccess classes
	AttachDataSources method

Parameters:
phDatasetBuffer	HANDLE
	The handle of the ProDataset Buffer
phDataSource	HANDLE
	The handle of the DATA-SOURCE object
pcPairsList	CHARACTER
	pairs-list An optional character expression that evaluates to a comma-delimited list of field name pairs that specify a mapping between different field names in the data-source object buffer and the ProDataSet temp-table buffer
pcExceptList	CHARACTER
	An optional character expression that evaluates to a comma-separated list of fields in the ProDataSet object buffer that will not be populated with data from the data source (that is, fields to exclude). Use this option when it is easier to specify fields to exclude rather than include. You can specify except-fields or include-fields, but not both
Returns	LOGICAL
	Logical return value of the ATTACH-DATA-SOURCE method

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PROTECTED LOGICAL AttachDataSource (handle, handle, character, character, character)

Purpose:	Attaches a data-source object to a temp-table buffer in a ProDataSet
	object
Notes:	Filters out any white space character from the field lists to allow
	for human readable source code in the DataAccess classes
	AttachDataSources method

Parameters:
phDatasetBuffer	HANDLE
	The handle of the ProDataset Buffer
phDataSource	HANDLE
	The handle of the DATA-SOURCE object
pcPairsList	CHARACTER
	pairs-list An optional character expression that evaluates to a comma-delimited list of field name pairs that specify a mapping between different field names in the data-source object buffer and the ProDataSet temp-table buffer
pcExceptList	CHARACTER
	An optional character expression that evaluates to a comma-separated list of fields in the ProDataSet object buffer that will not be populated with data from the data source (that is, fields to exclude). Use this option when it is easier to specify fields to exclude rather than include. You can specify except-fields or include-fields, but not both
pcIncludeFields	CHARACTER
	An optional character expression that evaluates to a comma-separated list of fields to include in the ProDataSet object buffer, as an alternative to specifying fields to exclude in except-fields. Use this option when it is easier to specify fields to include rather than exclude. You can specify include-fields or except-fields, but not both. If you specify include-fields, you must set except-fields to the Unknown value (?)
Returns	LOGICAL
	Logical return value of the ATTACH-DATA-SOURCE method

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PROTECTED LOGICAL AttachDataSource (handle, IBufferDataSource)

Purpose:	Attaches a data-source object generated by an BufferDataSource
	instance to a temp-table buffer in a ProDataSet object
Notes:	Filters out any white space character from the field lists to allow
	for human readable source code in the DataAccess classes
	AttachDataSources method

Parameters:
phDatasetBuffer	HANDLE
	The handle of the ProDataset Buffer
poDataSource	Consultingwerk.OERA.IBufferDataSource
	The reference to the the BufferDataSource instance that manages a data-source object handle
Returns	LOGICAL
	Logical return value of the ATTACH-DATA-SOURCE method

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PROTECTED LOGICAL AttachDataSource (handle, IBufferDataSource, character)

Purpose:	Attaches a data-source object generated by an BufferDataSource
	instance to a temp-table buffer in a ProDataSet object
Notes:	Filters out any white space character from the field lists to allow
	for human readable source code in the DataAccess classes
	AttachDataSources method

Parameters:
phDatasetBuffer	HANDLE
	The handle of the ProDataset Buffer
poDataSource	Consultingwerk.OERA.IBufferDataSource
	The reference to the the BufferDataSource instance that manages a data-source object handle
pcPairsList	CHARACTER
	pairs-list An optional character expression that evaluates to a comma-delimited list of field name pairs that specify a mapping between different field names in the data-source object buffer and the ProDataSet temp-table buffer
Returns	LOGICAL
	Logical return value of the ATTACH-DATA-SOURCE method

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PROTECTED AttachDataSources ()

Purpose:	Attaches the DATA-SOURCE objects to the ProDataset Buffers
Notes:	ABSTRACT method in Consultingwerk.OERA.DataAccess, overridden in
	actual DataAccess objects
	Invoked in FetchData and SaveChanges

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PROTECTED CHARACTER BuildDataSourceQueryString (handle, IFetchDataRequest, character)

Purpose:	Returns the Query String to be used for the DATA-SOURCE of a ProDataset
	member buffer
Notes:	Wrapper to the access to the DSQueryString class to simplify overriding
	the query manipulation in a custom Data Access class or customer
	DataAccess base class override
	This method is used to provide the query string for non top-level buffers
	The returned Query String is based on the Query String that was provided
	(by the consumer) and the Source Default Query of the Data Access object

Parameters:
phBufferHandle	HANDLE
	The Handle of the ProDataset member buffer
poFetchDataRequest	Consultingwerk.OERA.IFetchDataRequest
	The FetchDataRequest object of the current request
pcQueryString	CHARACTER
	The query string provided by the consumer
Returns	CHARACTER
	The Query String to be used for the data source of the ProDataset member buffer

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PUBLIC CanFind (CanFindParameter)

Purpose:	Returns a TRUE value if a record is found that meets the specified
	FIND criteria; otherwise it returns FALSE. CAN-FIND does not make
	the record available to the Business Entity or it's caller.
Notes:	Result will be assigned to the Result property of the CanFindParameter
	instance

Parameters:
poParameter	Consultingwerk.OERA.CanFindParameter
	The CanFindParameter with the parameters for this call

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PROTECTED CommitChanges (handle)

Purpose:	This method is called from SaveChanges in the DA
	to do the actual database commit and any transaction-related
	validation logic for a buffer.
Notes:	This is taken directly from the OERI.
	- Note that in this sample that illustrates support for distributed
	business logic the DA saves the whole dataset in SaveChanges, so
	this is not currently called from the BE.
	- The event names are the same as in the OERI. The word "Trans"
	is somewhat misleading as the DA need to support large transactions.
	One could consider using a name that indicates that this is a row
	event instead.

Parameters:
phBuffer	HANDLE
	The handle of the after buffer to commit

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PUBLIC CountResultRecords (ICountRecordsRequest)

Purpose:	Counts the number of result records in the data source query
Notes:

Parameters:
poFetchDataRequest	Consultingwerk.OERA.ICountRecordsRequest
	The ICountRecordsRequest that also implements IFetchDataRequest

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PROTECTED LOGICAL DatasetBufferFill (handle, IFetchDataRequest)

Purpose:	Invokes the FILL method of a ProDataset member buffer
Notes:	Allows overriding this method in custom variants of the Data Access
	Errors thrown from or raised in the FILL call-back methods of the
	DataAccess class (SET-CALLBACK) will stop the Dataset from getting
	filled / filled further. However errors thrown from the call-back
	methods are not thrown from the FILL() method further up into a
	catch block or to the client.
	See http://knowledgebase.progress.com/articles/Article/P188375

Parameters:
phBuffer	HANDLE
	The handle of the proDataset
poFetchDataRequest	Consultingwerk.OERA.IFetchDataRequest
	The FetchDataRequest instance with the parameters for the current read
Returns	LOGICAL
	If the FILL is successful, this method returns TRUE. Otherwise, it returns FALSE.

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PROTECTED LOGICAL DatasetFill (handle, IFetchDataRequest)

Purpose:	Invokes the ProDataset FILL method
Notes:	Allows overriding this method in custom variants of the Data Access
	Errors thrown from or raised in the FILL call-back methods of the
	DataAccess class (SET-CALLBACK) will stop the Dataset from getting
	filled / filled further. However errors thrown from the call-back
	methods are not thrown from the FILL() method further up into a
	catch block or to the client.
	See http://knowledgebase.progress.com/articles/Article/P188375

Parameters:
phDataset	HANDLE
	The handle of the ProDataset
poFetchDataRequest	Consultingwerk.OERA.IFetchDataRequest
	The FetchDataRequest instance with the parameters for the current read
Returns	LOGICAL
	If the FILL is successful, this method returns TRUE. Otherwise, it returns FALSE.

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PROTECTED DefineReadEvents ()

Purpose:	TO-DO: Subscribe to ProDataset Event Handlers using SET-CALLBACK
	as needed
Notes:	ABSTRACT method in Consultingwerk.OERA.DataAccess, overridden in
	actual DataAccess objects
	Invoked in FetchData

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PROTECTED DetachDataSources ()

Purpose:	Detaches the DATA-SOURCE objects to the ProDataset Buffers
Notes:	ABSTRACT method in Consultingwerk.OERA.DataAccess, overridden in
	actual DataAccess objects
	Invoked in FetchData and SaveChanges

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PROTECTED CHARACTER ExpandTables (character)

Purpose:	Expands the FetchDataRequest:Tables parameter, in case it contains
	the * wild-card character
Notes:

Parameters:
pcTables	CHARACTER
	The initial Tables parameter
Returns	CHARACTER
	The tables parameter with the wild-cards expanded

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PUBLIC FetchData (IFetchDataRequest)

Purpose:	Fetch data from the data source
Notes:	poFetchDataRequest:Context property is used to control batching
	(forward/backwards) and the FindRowWhere/PreFetchOnFind
	The first entry by CHR(1) in the Context is CHR(2) delimited:
	1. Entry: RESTART-ROWID(s) - CHR(5) Delimited
	2. Entry: Find String
	3. Entry: PrefetchOnFind Value
	The poFetchDataRequest parameter may also be passed in as a
	FetchDataAccessRequest instance allowing further specific arguments
	to be passed that are only relevant to the DataAccess class

Parameters:
poFetchDataRequest	Consultingwerk.OERA.IFetchDataRequest
	The IFetchDataRequest object with the parameters for this call

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PUBLIC FetchDataByKeyTable (IFetchDataByKeyTableParameter)

Purpose:	Allows retrieve multiple DB records from a Business Entity based on
	a temp-table with key values
Notes:

Parameters:
poParameter	Consultingwerk.OERA.IFetchDataByKeyTableParameter
	The IFetchDataByKeyTableParameter with the data for this call

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PRIVATE FetchDataInternal (IFetchDataRequest)

Purpose:	Fetch data from the data source
Notes:	Internal version of the method. The attaching and de-attaching of
	the DataSources is no done in FetchData. The possible recursive call
	to fetch a complete LAST batch after FindRowWhere is calling into
	the method FetchDataInteral do not interfer with the attaching of
	the data-source's. SCL-621: This structure allows us to always deattach
	the data-sources when they should still be around (left over due to
	missing FINALLY-Block execution after STOP-Condition

Parameters:
poFetchDataRequest	Consultingwerk.OERA.IFetchDataRequest
	The IFetchDataRequest object with the parameters for this call

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PROTECTED ROWID FindRecord (character, handle, character, integer, integer)

Purpose:	Finds a record in the data source query and returns the ROWID ARRAY
	(used as RESTART-ROWID in FetchData)
Notes:	This method is kept for backwards compatibility as the FindRecord2
	method is now the actual working method

Parameters:
pcFindString	CHARACTER
	WHERE eCustomer.CustNum = 10
phBufferHandle	HANDLE
	The temp-table buffer handle
pcQueryString	CHARACTER
	The current data-source query string
piPrefetch	INTEGER
	The number of records to prefetch
piBatchSize	INTEGER
	The number of records to return to the client (total incl. prefetch)
Returns	ROWID
	The ROWID array of the records - that starts the resulting batch

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PROTECTED Consultingwerk.OERA.FindRecordResult FindRecord2 (character, handle, character, integer, integer)

Purpose:	Finds a record in the data source query and returns the ROWID ARRAY
	(used as RESTART-ROWID in FetchData)
Notes:

Parameters:
pcFindString	CHARACTER
	WHERE eCustomer.CustNum = 10
phBufferHandle	HANDLE
	The temp-table buffer handle
pcQueryString	CHARACTER
	The current data-source query string
piPrefetch	INTEGER
	The number of records to prefetch
piBatchSize	INTEGER
	The number of records to return to the client (total incl. prefetch)
Returns	Consultingwerk.OERA.FindRecordResult
	The FindRecordResult with the array of rowids and the information if a previous batch is available

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PROTECTED FindSourceBuffer (handle, logical)

Purpose:	Locates the matching record in the first source buffer of the given
	Dataset Buffer
Notes:

Parameters:
phBuffer	HANDLE
	The handle of a (after) ProDataset buffer
plExclusiveLock	LOGICAL
	Logical value indicating if the record should be locked exclusively

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PROTECTED HandleRecordLockedError (handle, SysError)

Purpose:	Handles a record locked error invoked during the SAVE-ROW-CHANGES
	method
Notes:	Allows customization to the Progress default error message

Parameters:
phBeforeBuffer	HANDLE
	The handle to befure buffer
poSysError	Progress.Lang.SysError
	The orignal error raised

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PROTECTED HANDLE InsertToDataSourceQuery (handle, IFetchDataRequest, character)

Purpose:	Creates a new Query to be used as a DATA-SOURCE for a ProDataset
	member buffer
Notes:	Wrapper to the access to the DSQueryString class to simplify overriding
	the query manipulation in a custom Data Access class or customer
	DataAccess base class override
	This Query is prepared based on the Query String that was provided
	(by the consumer) and the Source Default Query of the Data Access object

Parameters:
phBufferHandle	HANDLE
	The Handle of the ProDataset member buffer
poFetchDataRequest	Consultingwerk.OERA.IFetchDataRequest
	The FetchDataRequest object of the current request
pcQueryString	CHARACTER
	The query string provided by the consumer
Returns	HANDLE
	The handle of the Query that was created

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PROTECTED InvokeCommitChangesCallback (CommitCallbackTypeEnum, handle)

Purpose:	Invokes a CommitChangesCallback
Notes:	Provides a central location to handle error thrown from these
	callback methods. By default errors thrown will be thrown to the
	caller. By overriding this mehod customers can CATCH errors and add
	them to the ProDataset buffer ERROR-STRING etc.

Parameters:
poCommitCallbackType	Consultingwerk.OERA.Enum.CommitCallbackTypeEnum
	The CommitCallbackTypeEnum value describing the callback to be invoked
phBeforeBuffer	HANDLE
	The handle of the before-buffer (to determine the ROW-STATE)

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PROTECTED Consultingwerk.OERA.IDSQueryString NewDSQueryString (character, character)

Purpose:	Factory method for the DSQueryString objects
Notes:	It's not recommended that customers override this method, SCL-866
	Customers should rather override the two methods NewDSQueryString
	(pcQuery, pcBuffer, plFilterUsingInnerJoin) and NewDSQueryStringForKeyValueTable
	(pcQuery, pcBuffer, plFilterUsingInnerJoin, poFetchDataByKeyTableParameter,
	pcFieldPairs)

Parameters:
pcQuery	CHARACTER
	The Query String for the DSQueryString instance
pcBuffer	CHARACTER
	The Buffer Name for the DSQueryString instance
Returns	Consultingwerk.OERA.IDSQueryString
	The new IDSQueryString instance

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PROTECTED Consultingwerk.OERA.IDSQueryString NewDSQueryString (character, character, logical)

Purpose:	Factory method for the DSQueryString objects
Notes:	Customers should override this method as a factory for custom IDSQueryString
	implementations

Parameters:
pcQuery	CHARACTER
	The Query String for the DSQueryString instance
pcBuffer	CHARACTER
	The Buffer Name for the DSQueryString instance
plFilterUsingInnerJoin	LOGICAL
	Logical value indicating if the data source query should be using an inner join
Returns	Consultingwerk.OERA.IDSQueryString
	The new IDSQueryString instance

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PROTECTED Consultingwerk.OERA.IDSQueryString NewDSQueryStringForKeyValueTable (character, character, logical, IFetchDataByKeyTableParameter, character)

Purpose:	Factory method for the DSQueryStringForKeyValueTable objects
Notes:	Customers should override this method as a factory for custom
	DSQueryStringForKeyValueTable implementations

Parameters:
pcQuery	CHARACTER
	The Query String for the DSQueryString instance
pcBuffer	CHARACTER
	The Buffer Name for the DSQueryString instance
plFilterUsingInnerJoin	LOGICAL
	Logical value indicating if the data source query should be using an inner join
poFetchDataByKeyTableParameter	Consultingwerk.OERA.IFetchDataByKeyTableParameter
	The IFetchDataByKeyTableParameter instance with the parameter of the FetchDataByKeyTable method
pcFieldPairs	CHARACTER
	The originally attached field pairs
Returns	Consultingwerk.OERA.IDSQueryString
	The new IDSQueryString instance

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PROTECTED Consultingwerk.IQueryRowIdentifier NewQueryRowIdentifier ()

Purpose:	Overridable factory method to create an instance of the IQueryRowIdentifier
	class
Notes:

Returns	Consultingwerk.IQueryRowIdentifier
	The reference to the new instance of the IQueryRowIdentifier interface

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PROTECTED OnAfterSaveChanges (EventArgs)

Purpose:	Raises the AfterSaveChanges
Notes:

Parameters:
e	Consultingwerk.EventArgs
	The Consultingwerk.EventArgs with the data for the event

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PROTECTED OnAfterSavingRowChanges (SaveRowChangesEventArgs)

Purpose:	Raises the AfterSavingRowChanges event
Notes:

Parameters:
e	Consultingwerk.OERA.SaveRowChangesEventArgs
	The SaveRowChangesEventArgs with the data for this event

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PROTECTED OnBeforeSaveChanges (EventArgs)

Purpose:	Raises the BeforeSaveChanges
Notes:

Parameters:
e	Consultingwerk.EventArgs
	The Consultingwerk.EventArgs with the data for the event

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PROTECTED OnBeforeSavingRowChanges (SaveRowChangesEventArgs)

Purpose:	Raises the BeforeSavingRowChanges event
Notes:

Parameters:
e	Consultingwerk.OERA.SaveRowChangesEventArgs
	The SaveRowChangesEventArgs with the data for this event

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PROTECTED OnHandleCommitError (HandleCommitErrorEventArgs)

Purpose:	Raises the HandleCommitError
Notes:

Parameters:
e	Consultingwerk.OERA.HandleCommitErrorEventArgs
	The HandleCommitErrorEventArgs with the data for the event

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PROTECTED OnHandleCommitSysError (HandleCommitErrorEventArgs)

Purpose:	Raises the HandleCommitSysError
Notes:

Parameters:
e	Consultingwerk.OERA.HandleCommitErrorEventArgs
	The HandleCommitErrorEventArgs with the data for the event

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PUBLIC CHARACTER ParentRelationSourceQueryString (handle)

Purpose:	Returns the query string matching the DATA-RELATION field pairs
	referencing the source fields on the parent table
Notes:

Parameters:
phBuffer	HANDLE
	The child buffer of the relation
Returns	CHARACTER
	The source query string matching the data-relation criteria

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PUBLIC RepositionBackwards (handle, integer)

Purpose:	Reposition the given query backwards by the given number of records
Notes:	Overidable by child classes to implement custom behaviour

Parameters:
phQuery	HANDLE
	The query handle to reposition backwards
piNumRecords	INTEGER
	The number of records

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PROTECTED ROWID RepositionBackwards (handle, rowid[], integer)

Purpose:	Evaluates the ROWID from which the ProDataset FILL operation
	needs to start on a backwards fill operation
Notes:	This method may be overridden in a DataAccess object class
	This method is no longer used for the backwards batching.
	It is kept for backwards compability of customers code.

Parameters:
phQuery	HANDLE
	The Query Handle to reposition backwards
proRowids	ROWID
	The current ROWID Array
piBatchSize	INTEGER
	The number of records to reposition backwards
Returns	ROWID
	The array of starting ROWIDs for the next FILL operation

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PROTECTED SaveBuffer (handle)

Purpose:	Called from saveChanges to process changes
	for a single DataSet temp-table buffer.
Notes:	This is similar to the OERI BE version, but has no pre and
	post transaction hooks because:
	- This method might very well be called inside a transaction.
	- The BE supports hooks outside of the transaction scope.

Parameters:
phBuffer	HANDLE
	The handle of the after buffer

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PUBLIC SaveChanges ()

Purpose:	Save changes to physical storage
Notes:	This implementation of data access save traverses all records in order
to:
	- Allow the DA to control transactions, which cannot be directly
	controlled in distributed BL. Transaction control is a concern of
	the BL, but should not be contolled with TRANSACTION keyword.
	- Offer a course grained save interface from distributed BL
	- The default operation here is just a transaction per record
	- This simple sample does not use child relations to traverse
	the buffers as the OERI BE example. (A property that controls
	update order would give the same effect).
	- Traversing of child data from a parent would make sense if done for
	one parent record at a time.

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PROTECTED SaveRowChanges (handle)

Purpose:	Overridable method that executes SAVE-ROW-CHANGES on the before buffer
Notes:	Called from CommitChanges

Parameters:
phBeforeBuffer	HANDLE
	The handle of the before buffer

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PROTECTED SetDatasetBufferCallback (handle, character, character)

Purpose:	Sets's a ProDataset Buffer Callback-Method (BEFORE-FILL, AFTER-FILL, BEFORE-ROW-FILL, ...)
Notes:

Parameters:
phBuffer	HANDLE
	The ProDataset Buffer Handle to add the callback for
pcCallback	CHARACTER
	The DatasetBufferEventEnum value to add the callback method for
pcMethod	CHARACTER
	The name of the Method to register as a callback

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PROTECTED SetDatasetBufferCallback (handle, character, character, Object)

Purpose:	Sets's a ProDataset Buffer Callback-Method (BEFORE-FILL, AFTER-FILL, BEFORE-ROW-FILL, ...)
Notes:

Parameters:
phBuffer	HANDLE
	The ProDataset Buffer Handle to add the callback for
pcCallback	CHARACTER
	The DatasetBufferEventEnum value to add the callback method for
pcMethod	CHARACTER
	The name of the Method to register as a callback
poObject	Progress.Lang.Object
	The Object that contains the callback method

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PROTECTED SetDatasetCallback (character, character)

Purpose:	Sets's a ProDataset Callback-Method (BEFORE-FILL, AFTER-FILL)
Notes:

Parameters:
pcCallback	CHARACTER
	The DatasetEventEnum value to add the callback method for
pcMethod	CHARACTER
	The name of the Method to register as a callback

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PROTECTED SetDatasetCallback (character, character, Object)

Purpose:	Sets's a ProDataset Callback-Method (BEFORE-FILL, AFTER-FILL)
Notes:

Parameters:
pcCallback	CHARACTER
	The DatasetEventEnum value to add the callback method for
pcMethod	CHARACTER
	The name of the Method to register as a callback
poObject	Progress.Lang.Object
	The Object that contains the callback method

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PROTECTED Consultingwerk.IQueryRowIdentifier SkipRecords (integer, handle)

Purpose:	Returns the Query Row Identifier (ROWID) to be used when navigating
	that DATA-SOURCE query based on the Skip argument of the FetchDataRequest
Notes:	Typically used when paging from a JSDO/Kendo UI client, SCL-819, SCL-822

Parameters:
piSkipRecords	INTEGER
	The number of records to skip from the beginning
phBuffer	HANDLE
	The temp-table buffer who's data-source should be navigated using Skip
Returns	Consultingwerk.IQueryRowIdentifier
	The IQueryRowIdentifier identifying the restart rowid

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PUBLIC CHARACTER SourceColumn (character, character)

Purpose:	Returns the database field name matching a temp-table field name
	contained in a consumers query string (query string vs. temp-table
	definition)
Notes:	Call-back used by Consultingwerk.OERA.Query.DSQueryString (part of
DataAccess:FetchData	FetchData () query preparation
TO-DO:	Provide code for alternative mapping

Parameters:
pcTable	CHARACTER
	The temp table name to return the source (database table) field name for
pcColumn	CHARACTER
	The temp table column name to return the source (database table) field name for
Returns	CHARACTER
	The database field name mapped to the passed in temp-table field

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PUBLIC CHARACTER SourceDefaultQuery (character)

Purpose:	Returns the base query string used to retrieve data for the temp
	tables. This query string will be appended by the query provided by
	the consumer (FetchDataRequest object).
Notes:	Call-back used by Consultingwerk.OERA.Query.DSQueryString (part of
DataAccess:FetchData	FetchData () query preparation
TO-DO:	Provide code to return the DATA-SOURCE root query string

Parameters:
pcTable	CHARACTER
	The temp table name to return the source default (database) query string for
Returns	CHARACTER
	The base query string used to retrieve data for the given temp-table

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PROTECTED SuggestDataSourceIndex (handle, character)

Purpose:	Method allows enforcing specific indexes when populating child record
	of a data-relation. When the parent buffer and the child buffer are
	FILL'ed during the ProDataset:FILL() operation, we ensure the given index
Notes:	Allows to avoid situations where in a Order -> OrderLine data-relation
	when filtered by Orderline.ItemNum the itemnum index is choosen instead
	of the more efficient orderline index (both indexes provide one equality
	match, but itemnum is the alphabetically first index)
	This method should be called from the dataset's BEFORE-FILL call back
	Only processes the first buffer of the data-source query, as we assume,
	that the proper join criteria between the data-source query buffers
	is specified in the SourceDefaultQuery

Parameters:
phChildBuffer	HANDLE
	The handle of the child buffer
pcIndexName	CHARACTER
	The index name to use

Constructor Detail

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PUBLIC DataAccess (handle)

Purpose:	Constructor of the DataAccess objects
Notes:	Requires to pass a valid dataset handle

Parameters:
phDataset	HANDLE
	The handle of the Business Entity dataset

Event Detail

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PUBLIC AfterSaveChanges (Object, EventArgs)

Purpose:	Raised at the end of SaveChanges - within the database transaction
	block
Notes:

Parameters:
sender	Progress.Lang.Object
	The object that raised the AfterSaveChanges event
e	Consultingwerk.EventArgs
	The Consultingwerk.EventArgs with the data for the event

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PUBLIC AfterSavingRowChanges (Object, SaveRowChangesEventArgs)

Purpose:	Event raised after the execution of the SAVE-ROW-CHANGES method
	for an individul record in the DataAccessObject
Notes:

Parameters:
sender	Progress.Lang.Object
	The reference to the object that raised this event
e	Consultingwerk.OERA.SaveRowChangesEventArgs
	The SaveRowChangesEventArgs with the data for this event

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PUBLIC BeforeSaveChanges (Object, EventArgs)

Purpose:	Raised at the beginning of SaveChanges - within the database transaction
	block
Notes:	This is not a cancelable event - as we have already started the database
	transaction and really only errors should revert it at this point

Parameters:
sender	Progress.Lang.Object
	The object that raised the BeforeSaveChanges event
e	Consultingwerk.EventArgs
	The Consultingwerk.EventArgs with the data for the event

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PUBLIC BeforeSavingRowChanges (Object, SaveRowChangesEventArgs)

Purpose:	Event raised before the execution of the SAVE-ROW-CHANGES method
	for an individul record in the DataAccessObject
Notes:

Parameters:
sender	Progress.Lang.Object
	The reference to the object that raised this event
e	Consultingwerk.OERA.SaveRowChangesEventArgs
	The SaveRowChangesEventArgs with the data for this event

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PUBLIC HandleCommitError (Object, HandleCommitErrorEventArgs)

Purpose:	Raised to allow custom handling of AppError's (Application errors,
	e.g. from DB triggers) raised while performing the SaveRowChanges method
Notes:

Parameters:
sender	Progress.Lang.Object
	The object that raised the HandleCommitError event
e	Consultingwerk.OERA.HandleCommitErrorEventArgs
	The HandleCommitErrorEventArgs with the data for the event

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PUBLIC HandleCommitSysError (Object, HandleCommitErrorEventArgs)

Purpose:	Raised to allow custom handling of SysError's (Progress runtime errors)
	raised while performing the SaveRowChanges method
Notes:

Parameters:
sender	Progress.Lang.Object
	The object that raised the HandleCommitError event
e	Consultingwerk.OERA.HandleCommitErrorEventArgs
	The HandleCommitErrorEventArgs with the data for the event

Property Detail

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PROTECTED Consultingwerk.Framework.Collections.CharacterDictionary AssignSkipDictionary

Purpose:	Gets the reference to a CharacterDictionary with an entry per buffer
	(after-buffer name) as the key and the the skip-list of the SAVE-ROW-CHANGES
	method used as the value
Notes:	Entries in this Dictionary have preference over the AssignSkipList character list
	skip-list
	An optional character expression that evaluates to a comma-separated
	list of field names for fields that should not be assigned after a
	new row is created (that is, fields to skip). For example, a key
	field or other fields assigned a value by a CREATE database trigger.

Returns	Consultingwerk.Framework.Collections.CharacterDictionary

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PUBLIC CHARACTER AssignSkipList

Purpose:	Gets and sets the skip-list of the SAVE-ROW-CHANGES method used as
	the skip-list of the SAVE-ROW-CHANGES method used in CommitChanges
	method
Notes:	This property is depricated now. Please use the AssignSkipDictionary
	class now.

Returns	CHARACTER

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PUBLIC CHARACTER CUSTOM_LOG_ENTRY

Purpose:	Gets the custom log file entry used by the DataAccess class
Notes:

Returns	CHARACTER

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PUBLIC HANDLE DatasetHandle

Purpose:	Gets the reference to the Dataset handle used by this Data Access
	object
Notes:	The Data Access object will typically be working on the ProDataset
	instance of a Business Entity (owner of the ProDataset)

Returns	HANDLE

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PROTECTED LOGICAL DataSourcesAttached

Purpose:	Returns if the DataSources are currently attached
Notes:

Returns	LOGICAL

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PROTECTED Consultingwerk.OERA.IFetchDataRequest FetchDataRequest

Purpose:	Returns the reference to the current IFetchDataRequest instance
Notes:	Allows accessing the IFetchDataRequest instance during ProDataset
	event call back and during the AttachDataSources method

Returns	Consultingwerk.OERA.IFetchDataRequest

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PUBLIC LOGICAL FilterUsingInnerJoin

Purpose:	Instructs the Query-Builder in method BuildQueryString to remove
	an eventually present OUTER-JOIN keyword from the source default
	query when filtering on a ceratin table.
Notes:	This allows to filter Customers by SalesRep fields in a Query:
	FOR EACH Customer, FIRST SalesRep OF Customer OUTER-JOIN
	The property is forwarded to the constructor of the DSQueryString
	class.
	See Bug 2609 for a detailled discussion on the new functionality

Returns	LOGICAL

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PUBLIC LOGICAL ForceApplyQueryOnChildTables

Purpose:	Allows to force applying the Source Default Query to child tables
	even when no filter expression was provided by the consumer
Notes:	When set to TRUE the FetchData method will assume a default
	"FOR EACH <temp-table-name>" query from the client, rather than an
	empty query string
	Useful when the source default query is required to filter out records
	even when dependent on the parent table relation (e.g. when records
	with certain statusses are filterred out)

Returns	LOGICAL

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PUBLIC LOGICAL LogFetchDataDetails

Purpose:	Allows to turn on and off the logging of details of the
	FetchData method execution
Notes:

Returns	LOGICAL

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PROTECTED LOGICAL PrepareJoinedChildTableQueries

Purpose:	Gets and sets if the Data Access class should prepare the query on
	joined child tables during FetchData
Notes:	SCL-334: DataAccess does not prepare queries on child tables with
	joined query data sources

Returns	LOGICAL

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PROTECTED Consultingwerk.OERA.QueryPurposeEnum QueryPurpose

Purpose:	Returns the current purpose of the SourceDefaultQuery callback
Notes:	Only valid while the SourceDefaultQuery method is executed, allows
	to return different/optimized queries for differnt usages of
	the data source query, see SCL-258

Returns	Consultingwerk.OERA.QueryPurposeEnum

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PUBLIC Consultingwerk.OERA.Enum.RequestTypeEnum RequestType

Purpose:	Returns the type of the current request (FetchData/SaveChanges)
Notes:	Can be used in AttachDataSource etc. to adjust data sources for
	optimized read or save operations

Returns	Consultingwerk.OERA.Enum.RequestTypeEnum

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PROTECTED LOGICAL ThrowErrorsOnFillFailed

Purpose:	Gets and sets if errors (negative return-value) during the ProDataset
	FILL() method should cause an error thrown by the DataAccess class
Notes:	The default behaviour is not to throw errors to be consistent with
	the previous behaviour and the default behaviour of ProDatasets,
see:	http://knowledgebase.progress.com/articles/Article/P188375

Returns	LOGICAL

info@consultingwerk.de http://www.consultingwerk.de 26.08.2016 08:29:50