11. The method according to claim 7 , wherein in the establishing process, said XML mappings comprise lossy mappings.
7. A method of automated data integration comprising: establishing extensible markup language (XML) mappings between XML source schemas and an XML target schema, wherein said XML source schemas comprise data; and wherein said XML target schema comprises a set of constraints, said set of constraints comprising: data merging rules for integrating said data from multiple said XML source schemas comprising overlapping information; and nested equality-generating dependencies (NEGDs), said NEGDs comprising rules specifying that fields in two different data tuples must be merged; querying multiple XML source schemas through a common XML target schema, wherein said common XML target schema defines a set of terms and a structure that a target query refers to; rewriting said target query in terms of said XML source schemas based on said XML mappings; integrating said data based on said set of constraints; evaluating a union of a set of source queries, wherein said evaluating occurs at query run-time; and displaying results of said rewriting and said integrating to a user.