Showing posts with label SQLObject. Show all posts
Showing posts with label SQLObject. Show all posts

Tuesday, March 3, 2009

Existing database tables and SQLObject

Define the existing table "Bookmark" as a class in python:-

class Bookmark(SQLObject):

_fromDatabase = True # the table structure will be loaded from the database
BookmarkName = StringCol (dbName="bookmark_name")
# dbName is the name of the column in the database, BookmarkName is the name reference in code.
ProjectId = IntCol(dbName="project_id")

(Make sure the indentation is correct)

Connecting to an existing database using TurboGears framework

Your application would need a DB connection to access the database. A connection is how you tell SQLObject to locate your database. SQLObject is an object relational mapper, a software layer that maps data stored in a relational database to an object model in an object-oriented programming language. The connection string resembles a URI in the following format:


scheme://[user[:password]@]host[:port]/database[?parameters]
For instance:
postgres://user:pwd@localhost:5432/db


SQLObject provides a debug mechanism, which can be turned on easily by appending ?debug=True to the end of your database URI in the dev.cfg file.

postgres://user:pwd@localhost:5432/db?debug=True
This would publish the query generated onto the console.
..........

Define the existing table Bookmark as a class in model.py:-

class Bookmark(SQLObject):

_fromDatabase = True # the table schema be loaded from the database

BookmarkName = StringCol (dbName="bookmark_name")

ProjectId = IntCol(dbName="project_id")

# dbName is the name of the column in the database, BookmarkName is the name reference in code.

..........
Using the following code in controller.py you should be able to retrieve the second record from the Bookmark table

 
b=Bookmark.select()
print ": %s " % b[2].BookmarkName