1. A computer program product for the automatic creation of mapping definitions, the computer program product comprising: one or more computer readable storage media and program instructions stored on the one or more computer readable storage media, the program instructions comprising: program instructions to analyze an external data structure, wherein the external data structure has one or more elements; program instructions to determine a path length and a number of occurrences for each element of a first set of elements of the one or more elements; program instructions to generate at least one query statement for the first set of elements; and program instructions to generate mapping definitions based, at least in part, on the at least one generated query statement and the path length of each element of the first set of elements.