In order to get objects and object-sets in NObject O/R Mapping persistence layer, you can query by using OQL (Object Query Language) that based on native language.
l Using OQL conditional expression query to get object is as follows:
|
Customer c = Customer.GetByCriteria(om,
OQL.Criteria(NW.Customer.CustomerID).EQ("ALFKI")
); // ... |
|
or |
|
Customer c = Customer.GetByCriteria(om,
NW.Customer.CustomerID == "ALFKI"
); // ... |
l The conditional expression above can be complex at will as follows:
|
SelectQuery selectQuery = OQL
.Select(NW.Order.CustomerID)
.From(NW.Order)
.Where(NW.Order.ShipCity == " Customer c = Customer.GetByCriteria(om,
NW.Customer.CustomerID.In(selectQuery) ); |
Or:
|
Customer c = Customer.GetByCriteria(om,
NW.Customer.CustomerID.In(OQL
.Select(NW.Order.CustomerID)
.From(NW.Order)
.Where(NW.Order.ShipCity == "
) ); |
l The way to get object-set is similar, a sample is as follows:
|
ObjectSet customers = om.GetObjectSet(NW.Customer,
NW.Customer.CustomerID.In(OQL
.Select(NW.Order.CustomerID)
.From(NW.Order)
.Where(NW.Order.ShipCity == "
)
); // ... |
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