大约有 49,000 项符合查询结果（耗时：0.0785秒） [XML]
mongodb group values by multiple fields
...takes an "pipeline" expression as an argument instead of the "localFields" and "foreignFields" options. This then allows a "self-join" with another pipeline expression, in which we can apply $limit in order to return the "top-n" results.
db.books.aggregate([
{ "$group": {
"_id": "$addr",
"...
Ruby: How to get the first character of a string
...= "Smith"
first_name = "John"
Then you can get the initials very cleanly and readably:
puts first_name.initial # prints J
puts last_name.initial # prints S
The other method mentioned here doesn't work on Ruby 1.8 (not that you should be using 1.8 anymore anyway!--but when this answer was p...
Multiple submit buttons on HTML form – designate one button as default [duplicate]
...n; }
#buttons input { float: right; }
will effectively reverse the order and thus the "Next" button will be the value triggered by hitting enter.
This kind of technique will cover many circumstances without having to resort to more hacky JavaScript methods.
...
Why doesn't indexOf work on an array IE8?
The below function works fine on Opera, Firefox and Chrome. However, in IE8 it fails on the if ( allowed.indexOf(ext[1]) == -1) part.
...
AngularJs $http.post() does not send data
...
I had the same problem using asp.net MVC and found the solution here
There is much confusion among newcomers to AngularJS as to why the
$http service shorthand functions ($http.post(), etc.) don’t appear to
be swappable with the jQuery equivalents (jQuery....
Rails has_and_belongs_to_many migration
I have two models restaurant and user that I want to perform a has_and_belongs_to_many relationship.
4 Answers
...
“Bitmap too large to be uploaded into a texture”
I'm loading a bitmap into an ImageView, and seeing this error. I gather this limit relates to a size limit for OpenGL hardware textures (2048x2048). The image I need to load is a pinch-zoom image of about 4,000 pixels high.
...
How to edit a node module installed via npm?
...to the source.
If the changes affect functionality of the overall module, and may be useful to others, you may want to contribute to the original source on github and look for the change to be implemented.
If this is proprietary functionality that is needed, and would not help the development of t...
Can someone explain the right way to use SBT?
I'm getting out off the closet on this! I don't understand SBT. There, I said it, now help me please.
4 Answers
...
How to manage local vs production settings in Django?
What is the recommended way of handling settings for local development and the production server? Some of them (like constants, etc) can be changed/accessed in both, but some of them (like paths to static files) need to remain different, and hence should not be overwritten every time the new code is...