1. A system for retrieving data from a plurality of data sources, said system comprising: a first data source for storing first data; a second data source for storing second data; and a server computing device in communication with the first data source and the second data source, the server computing device programmed to: receive a query execution request comprising a query definition reference and a query parameter definition, wherein the query definition reference corresponds to a query definition that includes a first query block and a second query block; create a first executable query based on the first query block and the query parameter definition; create a second executable query based on the second query block and the query parameter definition; execute the first executable query at the first data source to create first query results; and execute the second executable query at the second data source to create second query results.