大约有 40,000 项符合查询结果（耗时：0.0625秒） [XML]
Best way to store date/time in mongodb
...ISODate()})
> db.test.insert({date: new Date()})
> db.test.find()
{ "_id" : ObjectId("..."), "date" : ISODate("2014-02-10T10:50:42.389Z") }
{ "_id" : ObjectId("..."), "date" : ISODate("2014-02-10T10:50:57.240Z") }
The native type supports a whole range of useful methods out of the box, which...
django: BooleanField, how to set the default value to true?
...fields/#django.forms.Field.initial ) like
class MyForm(forms.Form):
my_field = forms.BooleanField(initial=True)
If you're using a ModelForm, you can set a default value on the model field ( https://docs.djangoproject.com/en/2.2/ref/models/fields/#default ), which will apply to the resulting M...
Cannot overwrite model once compiled Mongoose
...y have a schema defined, and then you are defining the schema again. Generally what you should do is instantiate the schema once, and then have a global object call it when it needs it.
For example:
user_model.js
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var userSchema...
The order of elements in Dictionary
...when enumerating them:
foreach (KeyValuePair<string, string> kvp in _Dictionary.OrderBy(k => k.Value)) {
...
}
In framework 2.0 you would first have to put the items in a list in order to sort them:
List<KeyValuePair<string, string>> items = new List<KeyValuePair<str...
force Maven to copy dependencies into target/lib
...tions>
<execution>
<phase>install</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>${proj...
What's the point of 'const' in the Haskell Prelude?
...
It's useful for passing to higher-order functions when you don't need all their flexibility. For example, the monadic sequence operator >> can be defined in terms of the monadic bind operator as
x >> y = x >>= const y
It's somewhat neater than using a lambda
x >> y =...
Maven2: Missing artifact but jars are in place
... settings in the global or user settings.
Check you're using the Maven installation you expect. By default m2eclipse uses the embedder, if you have a separate installation you may want to configure m2eclipse to use the external installation so that CLI and Eclipse builds are consistent. This also en...
What is a JavaBean exactly?
...
A JavaBean is just a standard
All properties private (use getters/setters)
A public no-argument constructor
Implements Serializable.
That's it. It's just a convention. Lots of libraries depend on it though.
With respect to Serializable, from the API d...
CoffeeScript, When to use fat arrow (=>) over arrow (->) and vice versa
When building a class in CoffeeScript, should all the instance method be defined using the => ("fat arrow") operator and all the static methods being defined using the -> operator?
...
Examples of Algorithms which has O(1), O(n log n) and O(log n) complexities
...p of Statements with Time complexity as given in the question, here is a small list -
O(1) time
Accessing Array Index (int a = ARR[5];)
Inserting a node in Linked List
Pushing and Poping on Stack
Insertion and Removal from Queue
Finding out the parent or left/right child of a node in a tree store...