Abstract: Described is technology to translate between tree-structured documents and electronic storage such as a relational data store. A document may be composed from the data store or decomposed to a data store using a document mapping command. The document mapping command includes follow commands that associate the columns in one table with columns in another table and resolve these associations during composition or decomposition. These follow commands allow for the retrieval of data from the data store and for inserting and/or modifying the data store by way of applying deltas to the data store.