ICachedDataset

Description

The ICachedDataset interface contains properties and methods that are used to work with data source cache.

Comments

Data source cache is a clipboard organized in computer memory that contains certain number of source records handled at the moment. The following operations with cache are available: filtering, search of necessary data, and editing existing and creating new records. After saving changes, corresponding queries are created 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 the 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 put in cache.
	RecordCount	The RecordCount property returns the current number of cached records.
	RecordCountAll	The RecordCountAll property returns the total number of data source records that can be put to cache.
	RecordsBufferThreshold	The RecordsBufferThreshold property determines threshold number of cache records.
	RecRange	The RecRange property determines the number of records cached forward from the 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 put to the first record of cache.
	Cancel	The Cancel method cancels changes in the current record.
	CreateLookup	The CreateLookup method creates an object that searches values in data source cache.
	Delete	The Delete method deletes the current record.
	Edit	The Edit method opens data source in the current record editing mode.
	EofData	The EofData method returns True if the cursor is on the record corresponding to last record in initial source data.
	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 the current position and starts its editing.
	Last	The Last method goes to the last record in cache.
	Post	The Post method saves changes in the current record.
	Prior	The Prior method goes 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 data source cache.