The application of heterogeneous database general query in digital campus

Due to the phase features of campus digital construction, there is the phenomenon of different databases coexistence in different departments of many colleges. Therefore, how to effectively extract data from different data sources and enable data sharing becomes increasingly prominent. This subject originates from the heterogeneous database query operation in digital campus construction, first, generate the user´s query plan into XML format than then determine the legality. Analyze the content of XML format query language, set up the query tree and query associated connection pool, and then achieve heterogeneous database query by query tree traversal and improve query efficiency by the way of intercurrence.