|
TCustomDADataSet.KeyFields Property |
|
|
|
TCustomDADataSet.KeyFields Property |
|
Used to build SQL statements for the SQLDelete, SQLInsert, and SQLUpdate properties if they were empty before updating the database.
property KeyFields: string;
TCustomDADataset uses the KeyFields property to build SQL statements for the SQLDelete, SQLInsert, and SQLUpdate properties if they were empty before updating the database. For this feature KeyFields may hold a list of semicolon-delimited field names. If KeyFields is not defined before opening a dataset, TCustomDADataset requests information about primary keys from server sending an additional query.
Assign the KeyFields property with a string containing the name of a field which will be later assigned with Oracle sequenced values. Beforehand Oracle sequence must be created and its name passed to the TOraDataSet.KeySequence property.
Sequences are generated when either Insert or Post method is called. Which of these two methods is used to modify the database is determined by the TOraDataSet.SequenceMode property.
Note: Though keys may be created across a number of table fields, sequence is generated only for the first field found in the KeyFields property.