1. A computer-implemented method of using a plurality of selectable database mappings, the method comprising: (a) providing a computerized stored library of a plurality of database mappings, each database mapping representing the manner in which one or more fields of one or more source databases maps to one or more fields of one or more target databases; and (b) when one or more source databases needs to be mapped to one or more target databases, selecting at least one of the database mappings from the library, and using the selected database mapping to perform a mapping.