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Possibility of duplicate Mongo ObjectId's being generated in two different collections?
...hey are generated on different machines.
Now if you were referring to the _id field in general, we do not require uniqueness across collections so it is safe to reuse the old _id. As a concrete example, if you have two collections, colors and fruits, both could simultaneously have an object like {_...
When saving, how can you check if a field has changed?
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Essentially, you want to override the __init__ method of models.Model so that you keep a copy of the original value. This makes it so that you don't have to do another DB lookup (which is always a good thing).
class Person(models.Model):
name = models.CharF...
When writing a directive in AngularJS, how do I decide if I need no new scope, a new child scope, or
...gs ('=').
On self-contained components, it doesn't make sense to need to apply other directives or attributes on it because it exists by itself. Its style is governed by its own template (if necessary) and can have the appropriate content transcluded (if necessary). It's standalone, so we put it i...
How to Execute SQL Server Stored Procedure in SQL Developer?
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You don't need EXEC clause. Simply use
proc_name paramValue1, paramValue2
(and you need commas as Misnomer mentioned)
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cpuid汇编指令 - C/C++ - 清泛网 - 专注C/C++及内核技术
... cpuid
cmp eax, 80000004h
jb not_supported
mov di, offset CPU_name
mov eax, 80000002h
cpuid
call save_string
mov eax, 80000003h
cpuid
...
Handler is abstract ,cannot be instantiated
I am trying to use a Handler in my app. But when i instantiate it like this:
6 Answers
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When to use in vs ref vs out
...f myfuncOut and myfuncRef are identical as expected.
outRefTest.myfunc:
IL_0000: nop
IL_0001: ldc.i4.0
IL_0002: starg.s 00
IL_0004: ldarg.0
IL_0005: stloc.0
IL_0006: br.s IL_0008
IL_0008: ldloc.0
IL_0009: ret
outRefTest.myfuncOut:
IL_0000: ...
How to avoid having class data shared among instances?
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You want this:
class a:
def __init__(self):
self.list = []
Declaring the variables inside the class declaration makes them "class" members and not instance members. Declaring them inside the __init__ method makes sure that a new instance of th...
Combining two expressions (Expression)
...itor
: ExpressionVisitor
{
private readonly Expression _oldValue;
private readonly Expression _newValue;
public ReplaceExpressionVisitor(Expression oldValue, Expression newValue)
{
_oldValue = oldValue;
_newValue = newValue;
...
Removing multiple keys from a dictionary safely
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Why not like this:
entries = ('a', 'b', 'c')
the_dict = {'b': 'foo'}
def entries_to_remove(entries, the_dict):
for key in entries:
if key in the_dict:
del the_dict[key]
A more compact version was provided by mattbornski using dict.pop()
...