1. A method for defining data transfer from a database into a hierarchical structure, the method comprising: generating a tagging tree that corresponds to a mapping between a relational database and a hierarchical data structure, the tagging tree comprising a plurality of nodes, at least one of the nodes having a node type, selected from the group of node types consisting of execution node, data node, binding node, attribute node, and element node; traversing at least one node of the tagging tree; retrieving, in response to traversing an execution node, a data object from the at least one relational database as specified in the execution node; and inserting, in response to a data node and based upon the mapping, the data object into an output conforming to the hierarchical structure.