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MongoDB/NoSQL: Keeping Document Change History
... changes to one or more specific entities in a database. I've heard this called row versioning, a log table or a history table (I'm sure there are other names for it). There are a number of ways to approach it in an RDBMS--you can write all changes from all source tables to a single table (more of...
Reliable method to get machine's MAC address in C#
...work across OS. Any ideas? I have been scraping the output of "ipconfig /all" but this is terribly unreliable as the output format differs on every machine.
...
C++ display stack trace on exception
...re details.
On MSVC then you can use the StackWalker library that handles all of the underlying API calls needed for Windows.
You'll have to figure out the best way to integrate this functionality into your app, but the amount of code you need to write should be minimal.
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MongoDB Many-to-Many Association
... user document:
{name:"Joe"
,roles:["Admin","User","Engineer"]
}
To get all the Engineers, use:
db.things.find( { roles : "Engineer" } );
If you want to maintain the roles in separate documents then you can include the document's _id in the roles array instead of the name:
{name:"Joe"
,roles:...
Python list subtraction operation
... [1,2] you will get empty list. [1,1,2,2] - [2] gives [1,1] So it is not really list substraction, it is more like "List from List X without elements from set Y".
– Alfred Zien
Feb 6 '16 at 10:25
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How to write log base(2) in c/c++
...mpiler doesn't know that log10 will return the same value every time. For all the compiler knows, log10(2) could return different values on successive calls.
– abelenky
Jun 17 '10 at 21:24
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Hash Map in Python
...res the keys to strings which are also valid Python identifiers (and internally, this also creates a dictionary).
– user395760
Jan 2 '12 at 17:31
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How to identify server IP address in PHP
... This is NOT the server address! This is the address the remote browser calls the server, which is under control of the remote user. Use the answer by John K instead
– Ariel
Feb 12 '15 at 10:36
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Where can I learn how to write C code to speed up slow R functions? [closed]
...ds C++ and Rcpp to be much more like writing R than writing C++. YMMV and all that.
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获取文件系统映像及恢复删除的数据（FAT文件系统格式描述） - C/C++ - 清泛...
...iGetClassDevs(&CLSID_DeviceInstance, NULL, NULL, DIGCF_PRESENT); //getting all devices with a removable disk guid
if ( INVALID_HANDLE_VALUE == hDevInfo )
{
return devInfos;//exit if there are no devices
}
try
{
st...