1. A computer-implemented system comprising at least one processor coupled to at least one machine-readable storage medium storing instructions executable by the at least one processor to implement: a transformation component configured to receive a canonical representation of an object-oriented query in a form of a command tree structure with nodes representing at least one of entity constructs or expressions associated with computational operations and data types; a plan compilation component configured to transform the canonical representation into a flattened command tree; a data model platform configured to provide services common to a plurality of disparate application frameworks, the services including support of the object-oriented query via object-relational mappings; a data reader object configured to return results from execution of the flattened command tree against a relational database; a column mapper configured to assemble the results into a nested instruction-type command tree; a query processor component; a sessions and transactions component; an object cache including a session cache and an explicit cache; a services component configured to perform change tracking and conflict detection; a cursors and rules component; a business logic hosting component; and a persistence and query engine configured to provide core persistence and query services.