In Database Management System (DBMS) is collection of interrelated data and set of programs to access and modify the data. In Relational DBMS (RDBMS), data is organized inform of tables. In order to retrieve information from the database, the end user requires the knowledge of database query language such as Structured Query Language (SQL). However, not every user is able to write SQL queries a...

Many information systems are implemented as application programs connected to a database system. A characteristic problem of such systems is the famous impedance mismatch, i.e., the conceptual distance between the programming and the database languages. The traditional solution is to implement an interface that transforms one representation into the other. Commercial database systems ooer prepr...

In the theory of database systems [1], a database query is defined as a function that maps relational databases to relations. This definition models the situation in practice where one applies an SQL query to a database instance and receives a set of output tuples as the answer to the query on that database. The problem of relational database query induction is then naturally stated as follows:...

In this paper, we first define a logical theory representing an XML database supporting XPath as query language and XUpdate as modification language. We then extend our theory with predicates allowing us to specify the security policy protecting the database. The security policy includes rules addressing the read and write privileges. We propose axioms to derive the database view each user is p...

Zagazig, Egypt ABSTRACT In the present computing world, most new-generation database applications need for intelligent interface to enhance efficient interactions between database and the users. Database query language SQL could be difficult to the non-expert users and learning these formal queries takes a lot of time. In this paper, we discussed mapping of natural language queries to SQL rathe...

In this paper, we define a security model [14] for a native XML database which supports the XUpdate language. Our model is inspired by the SQL security model which is the most famous security model for database. We first define a generic access control model for tree data structures. Then, we apply our model to an XML database which supports the Xupdate language.