Date of Award


Document Type


Degree Name

Master of Science (MS)


Computer Science

First Advisor

Dr. Zhengxin Chen

Second Advisor

Dr. Parvathi Chundi

Third Advisor

Dr. Peter Wolcott


Today’s search engines make it easier for the user to browse and query the online available data. But when it comes to structured data, the queries have to be structured too, in order to retrieve the data. This makes it difficult for novice users, with no knowledge of the underlying schema or query language, to access the relational data. Therefore, to query the structured data in an unstructured language of web, there is a need to map the user keyword queries to their equivalent SQL format. This research is intended to bridge the gap by introducing a framework named STRUCT. Unlike most of the existing work which pays very little attention to the contextual information provided by the user, our approach takes these details into account to elucidate the implied structural information necessary for constructing the SQL clauses. One fundamental issue on keyword search in traditional databases is how to interpret users’ information needs behind keywords they provided. A common approach of many prototype systems is to make such interpretation as a designer’s choice (such as imposing AND or OR semantics, or a combination), leaving no choice to users. A much more meaningful approach would be allowing users themselves to specify the required semantics through contextual information. So can we build a system which stays with the simplicity of Keyword search, yet can incorporate the contextual information provided in the user query? STRUCT answers this question by taking English language queries involving intended keywords. Instead of resorting on a full-fledged natural language processing, the unneeded words in the queries are discarded. Only the specific contextual information along with the keywords containing database contents will be used to construct SQL queries. The contextual information is used to interpret the meaning of the queries, including the semantics involving AND,OR and NOT. In this thesis we describe the architecture of STRUCT, procedure of English query processing (parsing), basic idea of the grouping algorithm, SQL query construction and sample results of experiments.


A Thesis Presented to the Department of Computer Science and the Faculty of the Graduate College University of Nebraska In Partial Fulfillment of the Requirements for the Degree. Copyright 2012 Rajvardhan Patil.

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