Database

This project requires creating user-defined database. A Simplified Relational Database (draft) 1. Database definition: users are able to define the format of DB(s)--number of fields, name and type, more importantly, links with other database(s). For instance, stud.id=[login to view URL] means the fact that the field "id" in the DB stud is the same as the "stdid" field in the DB course. 2. Database population/update: users are able to input new records, update/ delete exising records. A chain of actions could be triggered when a record is deleted. E.g., if a student should be deleted from the stud DB, then all records in other DB(s) related to this student should be deleted as well, say, in the course DB. (you may embed this functionality into the SQL manipulation language, but it is not required.) 3. Database manipulation: users are able to pose queries to the DBs by use of a simple SQL like language--design a parser which can recognize and carry out functionalities defined by, e.g., the following example: SELECT [login to view URL] [login to view URL] [login to view URL] FROM stud AND course WHERE stud.id=123456789 AND [login to view URL] < 3 SORTED BY [login to view URL] The words with upper case are keywords for this simple language.