大约有 18,000 项符合查询结果（耗时：0.0335秒） [XML]
How to change the type of a field?
...
Had a situation where I needed to convert the _id field as well as not conflict with other indexes: db.questions.find({_id:{$type:16}}).forEach( function (x) { db.questions.remove({_id:x._id},true); x._id = ""+x._id; db.questions.save(x); });
...
How can I create directory tree in C++/Linux?
...he standard header <filesystem> with
function
std::filesystem::create_directories
which should be used in modern C++ programs.
The C++ standard functions do not have the POSIX-specific explicit
permissions (mode) argument, though.
However, here's a C function that can be compiled with C++ com...
Where is SQL Server Management Studio 2012?
... work, so I did the following and it did: 1. Found the SQLManagementStudio_x86_ENU.exe for 2008 and ran it via the command prompt like so: SQLManagementStudio_x86_ENU.exe /action=uninstall /features=Tools 2. Did the same thing to uninstall 2012 3. Restarted my computer 3. Reinstalled SSMS 2012 u...
Converting string from snake_case to CamelCase in Ruby
... you're using Rails, String#camelize is what you're looking for.
"active_record".camelize # => "ActiveRecord"
"active_record".camelize(:lower) # => "activeRecord"
If you want to get an actual class, you should use String#constantize on top of that.
"app_user".came...
django admin - add custom form fields that are not part of the model
....models import YourModel
class YourModelForm(forms.ModelForm):
extra_field = forms.CharField()
def save(self, commit=True):
extra_field = self.cleaned_data.get('extra_field', None)
# ...do something with extra_field here...
return super(YourModelForm, self).save(c...
Application not picking up .css file (flask/python)
...ride it.
Your directory structure for css should be like:
/app
- app_runner.py
/services
- app.py
/templates
- mainpage.html
/static
/styles
- mainpage.css
Notice that your /styles directory should be under /static
Then, do this
<link re...
Best way to do multi-row insert in Oracle?
...
This works in Oracle:
insert into pager (PAG_ID,PAG_PARENT,PAG_NAME,PAG_ACTIVE)
select 8000,0,'Multi 8000',1 from dual
union all select 8001,0,'Multi 8001',1 from dual
The thing to remember here is to use the from dual statement.
(source)
...
Map Tiling Algorithm
...le:Object, degrees:uint):void
{
// http://www.flash-db.com/Board/index.php?topic=18625.0
var midPoint:int = tileDimension/2;
var point:Point=new Point(tile.x+midPoint, tile.y+midPoint);
var m:Matrix=tile.transform.matrix;
m.tx -= point.x;
m.ty -= point.y;
m.rotate (degree...
Which SQL query is faster? Filter on Join criteria or Where clause?
...
# explain analyze select e.* from event e join result r on e.id = r.event_id and r.team_2_score=24;
QUERY PLAN
-------------------------------------------------------------------------------------...
Difference between fprintf, printf and sprintf?
...on>
#include <stdarg.h>
#include <stdio.h>
struct exception_fmt : std::exception
{
exception_fmt(char const* fmt, ...) __attribute__ ((format(printf,2,3)));
char const* what() const throw() { return msg_; }
char msg_[0x800];
};
exception_fmt::exception_fmt(char const* fm...