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Add new field to every document in a MongoDB collection
...
> db.foo.find()
> db.foo.insert({"test":"a"})
> db.foo.find()
{ "_id" : ObjectId("4e93037bbf6f1dd3a0a9541a"), "test" : "a" }
> item = db.foo.findOne()
{ "_id" : ObjectId("4e93037bbf6f1dd3a0a9541a"), "test" : "a" }
> db.foo.update({"_id" :ObjectId("4e93037bbf6f1dd3a0a9541a") },{$set :...
Is there Selected Tab Changed Event in the standard WPF Tab Control
...
I tied this in the handler to make it work:
void TabControl_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (e.Source is TabControl)
{
//do work when tab is changed
}
}
sh...
HTML anchor link - href and onclick both?
...ing a clean HTML Structure, you can use this.
//Jquery Code
$('a#link_1').click(function(e){
e . preventDefault () ;
var a = e . target ;
window . open ( '_top' , a . getAttribute ('href') ) ;
});
//Normal Code
element = document . getElementById ( 'link_1' ) ;
element . onClick...
Python: reload component Y imported with 'from X import Y'?
... This doesn't seem to work always. I have a module Foo which has an __init__.py that fetches a submodule... I'll post an answer as a counterexample.
– Jason S
Oct 17 '17 at 22:32
...
ERROR:'keytool' is not recognized as an internal or external command, operable program or batch file
... C:\Program Files\Java\jdk1.6.0_21\bin>keytool -list -alias androiddebugkey -keystore .android\debug.keystore -storepass android -keypass android. the error i got is keytool error: java.lang.Exception: Key...
How do I detect whether a Python variable is a function?
...obj)
If this is for Python 3.x but before 3.2, check if the object has a __call__ attribute. You can do this with:
hasattr(obj, '__call__')
The oft-suggested types.FunctionTypes approach is not correct because it fails to cover many cases that you would presumably want it to pass, like with bui...
Deprecated: mysql_connect()
...em.
The way with MySQLi would be like this:
<?php
$connection = mysqli_connect('localhost', 'username', 'password', 'database');
To run database queries is also simple and nearly identical with the old way:
<?php
// Old way
mysql_query('CREATE TEMPORARY TABLE `table`', $connection);
// Ne...
Debug Error \"pure virtual function call\" 原因解析 - 更多技术 - 清泛...
...
public:
virtual void virtualFunc(){}
};
Base* pB = new Derived;
__try
{
delete pB; // . . . b)
pB = NULL;
}
__except(EXCEPTION_EXECUTE_HANDLER){
}
pB->virtualFunc(); // . . . c)
在b)处析构Derived对象的时候，在其基类析构函数中a)处抛出了...
how to change any data type into a string in python
... you're writing your own class and you want str to work for you, add:
def __str__(self):
return "Some descriptive string"
print str(myObj) will call myObj.__str__().
repr is a similar method, which generally produces information on the class info. For most core library object, repr produces ...
Backwards migration with Django South
...r app should have a migrations directory, with files in it named like
0000_initial.py
0001_added_some_fields.py
0002_added_some_more_fields.py
0003_deleted_some_stuff.py
Normally, when you run ./manage.py migrate your_app, South runs all new migrations, in order. (It looks at the database tables ...