Navigation: ABC Library Reference > RelationManager > RelationManager Methods >====== Update (update record subject to referential constraints)  ====== |    |
Update( fromform ), VIRTUAL
| Update | Updates this object's primary file (see Me) subject to the specified referential integrity constraints. |
| fromform | A numeric constant, variable, EQUATE, or expression that indicates whether this method was called from a (form) procedure with field history (restore) capability. A value of zero (0) indicates no restore capability; a value of one (1) indicates restore capability. This allows the method to issue an appropriate message when the update fails. |
The Update method updates the current record in the primary file (see Me) applying any specified referential integrity constraints, then returns a value indicating its success or failure.
Implementation:
Update constraints are specified by the AddRelation method and they apply to the values in the linking fields. If the constraint is RI:Restrict, the method does not update the current record if the change would result in orphaned child records. If the constraint is RI:Cascade, the method updates the primary file record as well as the linking field values in any related child records. If the constraint is RI:None, the method unconditionally updates only the primary file record. If the constraint is RI:Clear, the method unconditionally updates the primary file record, and clears the linking field values in any related child records.
When a parent file has cascade set to true for its child files, a call to Update will not do the cascade unless the Save method is called prior to changing the value of the linking fields.
Return Data Type: BYTE
Example:
ChangeOrder ROUTINE
IF Relate:Orders.Update(0) !update subject to constraints
MESSAGE('Update Failed') ! if fails, acknowledge
ELSE ! otherwise
POST(Event:CloseWindow) ! shut down
END
See Also: AddRelation ,Save