TADDataSet.RefreshRecord Method

Rereads field values of the current record from a data source.

Group

Links

TADDataSet Class, TADDataSet Members, uADCompDataSet Namespace, Example, public, See Also

Parameters	Description
AClearRow: Boolean = True	When True, then the record fields will be initially erased.

Returns

True, if a record is refreshed. False, if a record is deleted from a dataset.

Description

Use RefreshRecord to discard all changes of the current record and reread it from a data source. A similar method, TDataSet.Refresh, replaces the entire contents of the dataset by re-executing SQL command.

To reread record the AnyDAC will perform the sequence of steps:

If is assigned OnUpdateRecord event handler, then it will be called with ARequest = arFetchRow.
If event handler is not assigned or it returns AAction = eaDefault, then:
- If is assigned TADAdaptedDataSet.UpdateObject and TADUpdateSQL.FetchRowSQL is not empty, then this SQL command will be executed.
- Otherwise AnyDAC will generate SELECT command rereading single row from database and will execute command.

If query to a data source will return no rows (probably a record is deleted), then when UpdateOptions.RefreshDelete is True a record will be removed from a dataset too, otherwise an exception will be raised. When AClearRow parameters is set to True (default value), then the record will be initially erased. Otherwise the read values will override the corresponding column values.

The method returns True, if a record is refreshed. And False, if it is deleted from a dataset.

Syntax

function RefreshRecord(AClearRow: Boolean = True): Boolean;

Example

ADQuery1.UpdateObject := ADUpdateSQL;
// PL/SQL block calling packaged procedure returning customer data by its ID
ADUpdateSQL.FetchRowSQL.Text := 'begin cust_pack.read_cust_data(:new_name, :new_company, :new_state, :old_id); end;';
// always is required to setup output parameters
with ADUpdateSQL.Commands[arFetchRow] do begin
  Params[0].ParamType := ptOutput;
  Params[0].DataType := ftString;
  Params[1].ParamType := ptOutput;
  Params[1].DataType := ftString;
  Params[2].ParamType := ptOutput;
  Params[2].DataType := ftString;
end;
...
ADQuery1.RefreshRecord;

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