Unit 'DB'	Package
[Overview][Constants][Types][Classes][Procedures and functions][Variables][Index]	[#fcl]

TDataSet.Open

Activate the dataset: Fetch data into memory.

Declaration

Source position: db.pas line 1933

public procedure TDataSet.Open;

Description

Open must be used to make the TDataset Active. It does nothing if the dataset is already active. Open initializes the TDataset and brings the dataset in a browsable state:

Effectively the following happens:

The BeforeOpen event is triggered.
The descendents InternalOpen method is called to actually fetch data and initialize fielddefs and field instances.
BOFis set to True
Internal buffers are allocated and filled with data
If the dataset is empty, EOF is set to true
State is set to dsBrowse
The AfterOpen event is triggered

Errors

If the descendent class cannot fetch the data, or the data does not match the field definitions present in the dataset, then an exception will be raised.

TDataset.Active		Is the dataset open or closed.
TDataset.State		Current operational state of the dataset.
TDataset.BOF		Is the cursor at the beginning of the data (on the first record).
TDataset.EOF		Indicates whether the last record has been reached.
TDataset.BeforeOpen		Event triggered before the dataset is opened.
TDataset.AfterOpen		Event triggered after the dataset is opened.

TDataSet.Open

Declaration

Description

Errors

See also