1. A method of combining properties and methods from a plurality of different database systems, the method comprising: executing a first broker service to interact with a first data source using a first protocol to generate a first business object, the first business object including a first property and a first method, the first business object being in a declarative format; executing a second broker service to interact with a second data source using a second protocol to generate a second business object, the first protocol being different than the second protocol, the second business object including a second property and a second method, the second business object being in the declarative format; and storing a combined business object including the first property, the first method, the second property, and the second method, the combined business object being in the declarative format.