Book Image

Mastering Object-oriented Python

By : Steven F. Lott, Steven F. Lott
Book Image

Mastering Object-oriented Python

By: Steven F. Lott, Steven F. Lott

Overview of this book

Table of Contents (26 chapters)
Mastering Object-oriented Python
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Some Preliminaries
Index

Processing application data with SQL


The examples in the previous sections show us what we can call procedural SQL processing. We've eschewed any object-oriented design from our problem domain objects. Rather than working with the Blog and Post objects, we're working with the data elements that SQLite can process: string, date, float, and integer values. We've used mostly procedural-style programming.

We can see that a series of queries can be done to locate a blog, all posts that are part of the blog, and all tags that are associated with a post associated with a blog. The processing would look like the following code:

query_blog_by_title= """
SELECT * FROM BLOG WHERE TITLE=?
"""
query_post_by_blog_id= """
SELECT * FROM POST WHERE BLOG_ID=?
"""
query_tag_by_post_id= """
SELECT TAG.*
FROM TAG JOIN ASSOC_POST_TAG ON TAG.ID = ASSOC_POST_TAG.TAG_ID
WHERE ASSOC_POST_TAG.POST_ID=?
"""
for blog in database.execute( query_blog_by_title, ("2013-2014 Travel",) ):
    print( "Blog", blog )
    for post...