SQLAlchemy的count很慢

http://docs.sqlalchemy.org/en/rel_0_8/orm/tutorial.html#counting

uall = User.query.count()
很慢 (subquery的關係?)

session.query(func.count(User.id)).scalar()
快多了

232,053的資料, 用time.time() 算

count(): 4.53022193909 sec
func.count: 0.17828607559 sec

[nginx] facebook canvas連nginx時出現 HTTP 405 Not allowed

Facebook是用POST去抓canvas/iFrame,
但是nginx處理static file預設不給POST,
workaround如下:

location / {
    error_page 405 =200 $uri;
    root /var/www/html/yoursite.com;
}

比較好的處理如下:

http://invalidlogic.com/2011/04/12/serving-static-content-via-post-from-nginx/

[SQLAlchemy] 不用primary key的table

table沒有設pirmary key會出現這個錯誤:

sqlalchemy.exc.ArgumentError: Mapper Mapper|FooTable|foo_table could not assemble any primary key columns for mapped table 'foo_table'

mapper要設:

"primary_key":(col1, col2)}

[Mac][git] git diff in Mac

如果有裝GitX的話，設定選"Enable Terminal Usage"，然後

git diff | gitx


或是XCode的FileMerge/opendiff也很好用，

git difftool -t opendiff -y

可以寫到.gitconfig的

[alias]

   df = difftool -t opendiff -y

[SQLAlchemy] foreign key constraint 問題

以不delete, SET NULL為例:

1. database level
db.Column(db.Integer, ForeignKey(db.ForeignKey('category.id',ondelete='SET NULL')))

2. pythen level
db.relationship(passive_deletes=True)

[Tools] 方便產生server response的Deployd

http://www.deployd.com/

Emacs 24 color theme 錯誤

是因為Emacs有內建color theme，語法改一下就好了。

參考:
http://batsov.com/articles/2012/02/19/color-theming-in-emacs-reloaded/