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Does Foreign Key improve query performance?
...n FK does not create an associated index, and you should create indexes on all FK fields to improve look up times.
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Short description of the scoping rules?
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Actually, a concise rule for Python Scope resolution, from Learning Python, 3rd. Ed.. (These rules are specific to variable names, not attributes. If you reference it without a period, these rules apply.)
LEGB Rule
Local — N...
Comparing two dictionaries and checking how many (key, value) pairs are equal
... will fail on values that aren't hashable.
– Tim Tisdall
Apr 10 '17 at 13:51
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Conversion failed when converting date and/or time from character string while inserting datetime
...pendent of the dateformat settings in your SQL Server and will NOT work in all situations!
or:
YYYY-MM-DDTHH:MM:SS for dates and times - note here: this format has dashes (but they can be omitted), and a fixed T as delimiter between the date and time portion of your DATETIME.
This is valid for...
Keyboard shortcut to paste clipboard content into command prompt window (Win XP) [closed]
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I personally use a little AutoHotkey script to remap certain keyboard functions, for the console window (CMD) I use:
; Redefine only when the active window is a console window
#IfWinActive ahk_class ConsoleWindowClass
; Close Comm...
filter for complete cases in data.frame using dplyr (case-wise deletion)
...data.frame for complete cases using dplyr? complete.cases with a list of all variables works, of course. But that is a) verbose when there are a lot of variables and b) impossible when the variable names are not known (e.g. in a function that processes any data.frame).
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Regular cast vs. static_cast vs. dynamic_cast [duplicate]
... twenty years, but there's one aspect of these languages that I've never really understood. I've obviously used regular casts i.e.
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Finding what methods a Python object has
Given a Python object of any kind, is there an easy way to get the list of all methods that this object has?
19 Answers
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Set the maximum character length of a UITextField
...ed in to itself with an empty string. This will crash because it never actually pasted the string in to itself. It will try to replace a part of the string that doesn't exist.
Fortunately you can protect the UITextField from killing itself like this. You just need to ensure that the range it propose...
Why am I getting tree conflicts in Subversion?
...h of my trunk and was merging changes from my trunk into my branch periodically and everything was working fine. Today I went to merge the branch back down into the trunk and any of the files that were added to my trunk after the creation of my branch were flagged as a "tree conflict". Is there a wa...