As a starter project for learning Python/PostgreSQL, I am building a Books database that stores information on the books on my bookshelf.
Say I have three tables. Table "books" contains rows for book_id, title, subtitle, ISBN. Table "authors" contains rows for author_id, author surname, author first names, biographical notes. Table "bookauthors" contains two rows: book_id, author_id. The bookauthors table links the books and authors tables. Scenario: I have a python script which creates web page listing all books in the database, and all authors for each book. My python script does essentially three things: 1. retrieve a list of all book_ids and book_titles. 2. for each book_id, query the bookauthors table and retrieve all author names for that book_id. 3. display it all out as an html table on a web page. The script works fine, if a little slow. I think that's because if I have 50 books in my database, my script performs 51 database queries (1 for all book names; then 1 for each book). A colleague of mine suggested that I could get away with two queries, 1 to read the book ids and titles, and 1 to read the bookauthors table to pull in *all* relations, and then do all the work in Python. I think I know where he's coming from, but I don't know where to begin. Any clues? Is there a specific name for this technique? -- http://mail.python.org/mailman/listinfo/python-list
