TDAMemoryDataset

From RemObjects Software

This is a Data Abstract Architecture entry
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Overview

TDataset descendant that stores data in local memory.

File

• uDAMemDataset

Declaration

TDAMemoryDataset = class(TDataset)

Hierarchy

• TDAMemoryDataset

Properties

Property	Type	Description
Active	Boolean	Open or close dataset.
AutoCompactRecords	Boolean	Allows you to compact records for decreasing required memory and increasing performance. Is recommended for read-only datasets. New mode is more appropriate for textdata which has big string fields and is filled only partially and it is less appropriate for "numeric" data. (integer/datatable/float/etc).
CloneSource	TDAMemoryDataset	Defines an external dataset allowing sharing of its data.
DetailFields	string	Holds the field or list of fields from the current dataset that makes up the foreign key of a Master/Detail relationship. These fields will be matched against the MasterFields from the MasterSource dataset.
FieldDefs	TFieldDefs	Collection of field definitions.
Filter	string	Defines the condition for selected records.
Filtered	Boolean	Indicates the dataset is filtered.
IndexDefs	TIndexDefs	Contains information about the indexes.
IndexFieldNames	string	Contains the names of fields which make up the index.
IndexName	string	Identifies an index.
MasterFields	string	Holds the field or list of fields from the MasterSource that makes up the primary key of a Master/Detail relationship. These fields will be matched against the DetailFields from the local dataset.
MasterSource	TDataSource	In a Master/Detail relationship, it specifies the dataset that acts as master for the dataset.
ReadOnly	Boolean	Manages whether the dataset is read-only (true) or not (false, default). If enabled, no changes to the data contained in the dataset will be permitted.
SortLocale	LCID	Defines the locale for sorting strings.
StoreStringAsReference	Boolean	Enables storing of string values by reference and is off by default. Enabling this option can be useful for long strings, but has some performance overhead. This property will be enabled automatically for strings longer than 4096 bytes.

Methods

Method	Description
ApplyRange	Applies a range to the dataset.
AddIndex	Adds index to dataset.
BookmarkValid	Checks whether the bookmark points to a valid record.
Cancel	Cancel data changes.
CancelRange	Removes any ranges currently in effect for the dataset.
CloneCursor	Sets CloneSource property to share the data belonging to another client dataset.
CompareBookmarks	Compares two bookmarks.
DeleteIndex	Removes index.
EditKey	Enables modification of the search key buffer.
FindKey	Searches for a record containing specified field values.
FindNearest	Moves the cursor to the record that most closely matches a specified set of key values.
GetFieldData	Fills buffer by field contents.
GetIndexNames	Returns the names of the fields that form the index.
GotoKey	Moves the cursor to a record specified by the current key.
GotoNearest	Moves the cursor to the record that most closely matches the current key.
Locate	Locates record by the values of key fields.
LocateByIndex	Locates the record by index.
Lookup	Locates the record by values of key fields and returns values of fields in this record.
LookupByIndex	Locates record by index and returns values of fields in this record.
Post	Applies data changes.
PrepareIndexForSorting	Prepares index for using by methods LocateByIndex and LookupByIndex.
SortOnFields	Sorts dataset by the fields set.
SetRange	Sets the starting and ending values of a range, and applies it.
EditRangeEnd	Enables changing the ending value for an existing range.
EditRangeStart	Enables changing the starting value for an existing range.
SetKey	Enables setting of keys and ranges for a dataset prior to a search.
SetRangeEnd	Indicates that subsequent assignments to field values specify the end of the range of rows to include in the dataset.
SetRangeStart	Indicates that subsequent assignments to field values specify the start of the range of rows to include in the dataset.

Events

Event	Description
AfterCancel	Fires after canceling changes to the dataset.
AfterClose	Fires after closing the dataset.
AfterDelete	Fires after deleting a record in the dataset.
AfterEdit	Fires after dataset editing ends.
AfterInsert	Fires after inserting a record into the dataset.
AfterOpen	Fires after opening the dataset.
AfterPost	Fires after applying changes to the dataset.
AfterRefresh	Fires after the dataset has been refreshed.
AfterScroll	Fires after the dataset has been scrolled.
BeforeCancel	Fires before canceling changes to the dataset.
BeforeClose	Fires before closing the dataset.
BeforeDelete	Fires before deleting a record in the dataset.
BeforeEdit	Fires before starting to edit the dataset.
BeforeInsert	Fires before inserting a record into the dataset.
BeforeOpen	Fires before opening the dataset.
BeforePost	Fires before applying changes to the dataset.
BeforeRefresh	Fires before starting to refresh the dataset.
BeforeScroll	Fires before starting to scroll the dataset.
OnCalcFields	Fires before changing calculated field values.
OnDeleteError	Fires on error during a delete.
OnEditError	Fires on error during an edit.
OnFilterRecord	Fires after applying a filter to the dataset.
OnNewRecord	Fires on adding new record to the dataset.
OnPostError	Fires on error while applying changes.

See Also

• Lists
  • Class List (Data Abstract for Delphi)
  • Interface List (Data Abstract for Delphi)
  • Enum List (Data Abstract for Delphi)
  • Data Types (Data Abstract)
  • File Types (Data Abstract)

Product: RemObjects Data Abstract
Current version: Data Abstract 'Vinci' (5.0)

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