querying.rst

Querying

Get one entity identified by its key value

Get employee identified by 1 and print employee first name:

employee1 = northwind.entity_sets.Employees.get_entity(1).execute()
print(employee1.FirstName)

Get one entity identified by its key value which is not scalar

Get number of orderd units in the order identified by ProductID 42 and OrderID 10248:

order = northwind.entity_sets.Order_Details.get_entity(OrderID=10248, ProductID=42).execute()
print(order.Quantity)

Get all entities of an entity set

Print unique identification (Id) and last name of all employees:

employees = northwind.entity_sets.Employees.get_entities().select('EmployeeID,LastName').execute()
for employee in employees:
    print(employee.EmployeeID, employee.LastName)

Get entities matching a filter

Print unique identification (Id) of all employees with name John Smith:

smith_employees_request = northwind.entity_sets.Employees.get_entities()
smith_employees_request = smith_employees_request.filter("FirstName eq 'John' and LastName eq 'Smith'")

for smith in smith_employees.execute():
    print(smith.EmployeeID)

Get entities matching a filter in more Pythonic way

Print unique identification (Id) of all employees with name John Smith:

from pyodata.v2.service import GetEntitySetFilter as esf

smith_employees_request = northwind.entity_sets.Employees.get_entities()
smith_employees_request = smith_employees_request.filter(sef.and_(
                                                         smith_employees_request.FirstName == 'Jonh',
                                                         smith_employees_request.LastName == 'Smith'))
for smith in smith_employees_request.execute():
    print(smith.EmployeeID)

Get a count of entities

Print a count of all employees:

count = northwind.entity_sets.Employees.get_entities().count().execute()
print(count)

Get a count of entities via navigation property

Print a count of all orders associated with Employee 1:

count = northwind.entity_sets.Employees.get_entity(1).nav('Orders').get_entities().count().execute()
print(count)