General question on SQL queries in Java
Posted on 2004-04-06
I'm working on a web-based reporting application using Servlets/iText. I need to display reports (in PDF format) which contains info from mutliple tables. I used joins, and mutiple queries within loops to do some reports but these techniques do not work for all scenarios.
A simple example which illustrates my problem is given below.
eg. Student table - (student_id,student_name)
Course table - ( student_id,course_id)
To display course details of students, I join Student and Course tables, and I get a total of 5 records. In the report, I need to print a student name only once, and all courses for the student. However, if I loop thru the ResultSet, I get the student name for all records. How do I ensure that the student name is printed only once. I know I can do some 'ugly' manipulation in my Java code, to do the same. But, I'm looking for an elegant solution. Are they any Java classes that do the task I need to accomplish?
Any help would be greatly appreciated.
I understand that reporting tools like Jasper Reports allow queries to be attached to report templates and the task I mentioned is automatically taken care of by the tool.