In DObject O/R Mapping persistence layer's object-set, you can get sub-set from the existing object-set in each of methods that getting object-set from database, as follows:
l Filter a single field:
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Var orders : IObjectSet; subOrders: IObjectSet; begin orders := ObjectManager.GetObjectSet(NW.Order); // ... subOrders := orders.GetSubSet(NW.Order.EmployeeID, 1); end; |
l Filter multi-field:
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var orders : IObjectSet; subOrders: IObjectSet; filter : IOrder; begin orders := ObjectManager.GetObjectSet(NW.Order); // ... filter := TOrder.Create(nil); filter.EmployeeID := 1; filter.ShipVia := 1; subOrders := orders.GetSubSet(filter); end; |
l Using OQL:
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var orders : IObjectSet; subOrders: IObjectSet; begin orders := ObjectManager.GetObjectSet(NW.Order); // ... subOrders := orders.GetSubSet( OQL.Criteria(NW.Order.EmployeeID).EQ(1) ); end; |
Note: the OQL here doesn't support multi-table's Join, Sub-query, Case, Like and function.
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