1. A computer-implemented method of executing a query transaction by using data objects stored in database tables corresponding to entities of an organization, comprising: generating, via a processor, an entity relationship model to indicate a plurality of types of relationships between the entities; determining relationships between the database tables corresponding to the entities by using the entity relationship model, wherein the database tables are stored in a computer memory device; generating a graph based on the entity relationship model; generating sets of database elements representing the entities and corresponding data objects stored in the database tables, wherein the element sets are generated based on the generated graph; assigning ordering numbers to the database element sets and database elements included in the database element sets; and executing the query transaction by using the data objects in an order based on the ordering numbers.