Schema¶

Schema module provides auto-generate relational database model as object based.

File/Class Invoke rules¶

/schema/__init__.py, DO NOT IMPLEMENT ANY CODE IN THIS FILE
/schema/blog/__init__.py, BlogSchema > schema.blog
/schema/blog/articles.py, ArticlesSchema > schema.blog.articles
/schema/blog/comments.py, CommentsSchema > schema.blog.comments

Table migration(create or alter) will be executed by invoking .migrate() method manually. For example, you can migrate comments table with invoking schema.blog.comments.migrate() method.

There are 2 types of schema. One is __dsn__ specifier and another one is table describer. __init__.py file of each directory must be __dsn__ specifier. and child .py files are must be table describer.

Here is a __dsn__ specifier example (/schema/blog/__init__.py):

from dp_tornado.engine.schema import Schema as dpSchema


class BlogSchema(dpSchema):
    __dsn__ = 'tests.model_test/drv_mysql_test'

and Here is a table describer example (/schema/blog/comments.py):

from dp_tornado.engine.schema import Table as dpTable
from dp_tornado.engine.schema import Schema as dpSchema
from dp_tornado.engine.schema import Attribute as dpAttribute

class CommentsSchema(dpSchema):
    __table_name__ = 'comments'

    __engine__ = 'InnoDB'
    __charset__ = 'utf8'

    comment_id = dpAttribute.field(dpAttribute.DataType.BIGINT, ai=True, pk=True, nn=True, un=True, comment='Comment ID')
    article_id = dpAttribute.field(dpAttribute.DataType.BIGINT, nn=True, un=True, comment='Parent Article ID')
    author = dpAttribute.field(dpAttribute.DataType.VARCHAR(32), nn=True, comment='Author')
    comment = dpAttribute.field(dpAttribute.DataType.VARCHAR(128), nn=True, comment='Comment')

    primary_key = dpAttribute.index(dpAttribute.IndexType.PRIMARY, 'comment_id')

    idx_articles_author_and_comment = dpAttribute.index(dpAttribute.IndexType.INDEX, ('author', 'comment'))
    idx_articles_comment = dpAttribute.index(dpAttribute.IndexType.INDEX, 'comment')

    fk_comments_article_id = dpAttribute.foreign_key(('article_id', dpSchema.field().blog.articles, 'article_id'))