Our aim was to built a Query Processing Projects on Database Engine based on Relational Model . But, we have to reduce to our work and we finally come with an application that processes quiet large number SQL queries like SELECT, INSERT, UPDATE, DELETE and evaluation of some complicated expressions on single table. The application is built in JAVA and we have used BlueJ as development environment.

Query Processing Projects

We have used ZQL parser and modified its code as per our project requirements. 


  1. Persistent storage of data.

2.   Controlled redundancy.

3.   Support  queries of SELECT, DELETE ,  INSERT and UPDATE.

4.   Representation of some complex expressions like AND, OR , NOT , NOT  BETWEEN operators  on Single table . 


  1. Lack of Graphical user interface.
  2. Joins not supported.
  3. Works for Centralized Database only,  No support for client server   

 Future Directions 

Any data driven application will require the use of database engine. It  offers competitive performance in terms of speed, reliability and integrity with large number of expressions evaluation. Though, its scope is quite big. 

 1. It is limited to the centralized database, currently i.e. to a single user support. Here operations are performed on single table . 

2.  We can perform Join operations and use various optimization techniques like  heuristic approach and Cost based optimization for enhancing the performance of our application. 

3. Besides, we can use where other evaluations expressions like ORDER BY, GROUP BY , LIKE , NOT LIKE , COUNT, and other aggregate operations to extend the   performance of our application.