ICachedDataset

Description

The ICachedDataset interface contains properties and methods for operation with cache of data source.

Comments

The cache of data source is a clipboard organized in PC memory that contains certain quantity of source records handled at the moment. In a cache the filtering, search of necessary data, and also editing existing and creation of new records are available. After saving of changes, corresponding queries are organized in cache and data in corresponding data source is updated.

NOTE. If connection to file with data is executed by means of ODBC driver (text file, Microsoft Excel file and so on), working with records is executed only in the read-only mode. Adding/removing/editing of records is not supported.

Properties

	Property name	Brief description
	Filter	The Filter property returns filtering condition of data in cache.
	Filtered	The Filtered property determines current state of data filtering in cache.
	IndexFields	The IndexFields property determines sorting fields of data source cache.
	Instance	The Instance property returns the parent object of data source cache.
	MasterFields	The MasterFields property determines the list of fields of the main data source, by which the filtering of data in the linked data source is performed.
	MasterSource	The MasterSource property determines a data source that is the main one at linking of several data sources.
	ReadOnly	The ReadOnly property determines whether the data source is opened only for reading.
	RecNo	The RecNo property determines a index of the record on which the cursor is set in cache.
	RecordCount	The RecordCount property returns the current quantity of cached records.
	RecordCountAll	The RecordCountAll property returns total quantity of records in a data source, that can be placed to cache.
	RecordsBufferThreshold	The RecordsBufferThreshold property determines threshold number of cache records.
	RecRange	The RecRange property determines quantity of records cached forward from current position.
	State	The State property returns current state of data source.

Properties inherited from IDatasetInstance

	Property name	Brief description
	Dataset	The Dataset property returns a structure of data source.
	FieldDefs	The FieldDefs property returns structure of all data source fields.
	Fields	The Fields property returns collection of fields values of current data source record.

Methods

	Method name	Brief description
	AddCalculatedField	The AddCalculatedField method creates a calculated field in cache.
	Append	The Append method adds a record into the end of the table and starts its editing.
	Bof	The Bof method returns True if the cursor is set to the first record of cache.
	Cancel	The Cancel method cancels changes in current record.
	CreateLookup	The CreateLookup method creates an object that searches values in a cache of data source.
	Delete	The Delete method deletes current record.
	Edit	The Edit method switches data source into the mode of current record editing.
	EofData	The EofData method returns True if the cursor is on the record corresponding to last record in initial data of source.
	FetchToRecord	The FetchToRecord method loads records from data source to cache.
	GetFieldValue	The GetFieldValue method returns value of cached field without moving by records.
	Insert	The Insert method inserts record into a current position and starts its editing.
	Last	The Last method performs transition to the last record in cache.
	Post	The Post method saves changes in current record.
	Prior	The Prior method executes transition to the previous record.
	Truncate	The Truncate method deletes all records of data source.

Methods inherited from IDatasetInstance

	Method name	Brief description
	Close	The Close method closes data source.
	CreateBatchUpdate	The CreateBatchUpdate method creates updates of the data source data.
	Eof	The Eof method returns True if cursor is on the last record in data source, or if data source has no records.
	Execute	The Execute method runs query and returns the number of processed records.
	First	The First method moves to the first record of data source.
	Next	The Next method moves to the next record in the data source.
	OpenCached	The OpenCached method allows for working with cache of data source.