大约有 44,000 项符合查询结果（耗时：0.0798秒） [XML]
How do I create a slug in Django?
...
SlugFields set db_index=True by default, and also use a form field by default that has a validation regex to require valid slugs (if represented in a ModelForm or in the admin). You can do those things manually with a CharField if you prefer, it just makes the intention of your c...
Should you choose the MONEY or DECIMAL(x,y) datatypes in SQL Server?
...
"Never" is a strong word. "Money" is useful for casting results to that type for display to the user in a culture-sensitive way, but you're right that it's very bad to use for the calculations itself.
– Joel Coehoorn
Feb 24 '09 at...
SQLiteDatabase.query method
...
tableColumns
null for all columns as in SELECT * FROM ...
new String[] { "column1", "column2", ... } for specific columns as in SELECT column1, column2 FROM ... - you can also put complex expressions here:
new String[] { "(SELECT max(column1) ...
cartesian product in pandas
...
If you have a key that is repeated for each row, then you can produce a cartesian product using merge (like you would in SQL).
from pandas import DataFrame, merge
df1 = DataFrame({'key':[1,1], 'col1':[1,2],'col2':[3,4]})
df2 = DataFrame({'key':[1,1], 'col3':[...
Why is setTimeout(fn, 0) sometimes useful?
...consistently winning this race and attempting to set drop-down selection before the browser was ready, meaning that the bug would appear.
This race existed because JavaScript has a single thread of execution that is shared with page rendering. In effect, running JavaScript blocks the updating of th...
Django REST Framework: adding additional field to ModelSerializer
...
I think SerializerMethodField is what you're looking for:
class FooSerializer(serializers.ModelSerializer):
my_field = serializers.SerializerMethodField('is_named_bar')
def is_named_bar(self, foo):
return foo.name == "bar"
class Meta:
model = Foo
fields ...
Remove CSS class from element with JavaScript (no jQuery) [duplicate]
...
FWIW, this works for me on FF 7.0.1, and Chromium 16.0.910.0
– SW.
Oct 19 '11 at 1:38
6
...
registerForRemoteNotificationTypes: is not supported in iOS 8.0 and later
When trying to register for push notifications under iOS 8.x:
15 Answers
15
...
Full Screen DialogFragment in Android
...
And for me, I needed to use a RelativeLayout, but the dialog width wasn't adjusting properly to the contents, so I nested the RelativeLayout in a LinearLayout whose only child was the RelativeLayout... this triggered the proper w...
What is the “__v” field in Mongoose
...
@ExplosionPills for future reference: no. The version key is only incremented after operations that could cause a conflict, modifying array positions. Other updates won't increment it. The original release post explains it in detail: aaronhe...