Looking for oracle/sql tutorials and advice
Date: Sat, 26 Apr 2008 16:05:59 -0700 (PDT)
I'm teaching myself oracle and I am looking for some easy to follow step by step tutorials on oracle and sql. I already found a few good introductions which cover the basics (and possibly more) but the ones I have found so far seem to leave a lot of questions. Two things I would like to learn how to do are:
- How to 'unnormalise' so data. For example, I have followed a tutorial which shows how to normalise the contents of a column. So now the data has been put in a 'lookup' table and replaced with an ID (corresponding to the ID in the lookup table). How do I get the data back into the table it originally came from?
- Working with foreign keys. So far my studied have given me the impression that this is the key to how relational databases work - what makes them powerful/useful etc. But the only way I have seen to access this power is by creating queries, to make a report. But what about when one wants to add new data? e.g. in the Human Resources example (which comes with Oracle 10g Express) there is a table for employees, and also for departments. The department_id column on the employees table is constrained to the department_id column in the departments table. Now I want to create an application that displays the employees table, and also can display a form for adding new employees. On this form I would like there to be a button, next to each employee, which brings up the list of departments. From this I can select the department from this list. Is it possible to do something like this?
Thanks for any advice.
Michael Received on Sat Apr 26 2008 - 18:05:59 CDT