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Understanding :source option of has_one/has_many through of Rails
...'ve chosen to namespace the Dog::Breed, because we want to access Dog.find(123).breeds as a nice and convenient association.
Now, if we now want to create a has_many :dog_breeds, :through => :dogs association on Pet, we suddenly have a problem. Rails won't be able to find a :dog_breeds associati...
How do I create a unique constraint that also allows nulls?
...et_AllowNull
UNIQUE (TicketID, TicketUnique);
If IssueID 1 has ticket 123, the UNIQUE constraint will be on values (123, NULL). If IssueID 2 has no ticket, it will be on (NULL, 2). Some thought will show that this constraint cannot be duplicated for any row in the table, and still allows multip...
Mac OS X - EnvironmentError: mysql_config not found
...-Python (or pip3 install mysqlclient if using python 3)
If you did all those steps in the same order, and you still got an error, read on to the end, if, however, you did not follow these exact steps try, following them from the very beginning.
So, you followed the steps, and you're still geting ...
Dynamic instantiation from string name of a class in dynamically imported module?
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@jpennell you should post that as an answer, it's often more useful to be able to directly use the string returned by obj.__module__
– Anentropic
Aug 22 '14 at 12:42
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Get users by name property using Firebase
...:
Write to Firebase with a unique, known key:
ref.child('users').child('123').set({ "first_name": "rob", "age": 28 })
Append to lists with an auto-generated key that will automatically sort by time written:
ref.child('users').push({ "first_name": "rob", "age": 28 })
Listen for changes in data ...
Vim Insert Mode on Mac OS X
... LMAO. It seems like such a simple question, but I too was very lost. Hard to search for as well. I've always used the insert key. I was at a loss.
– Preston
Oct 14 '13 at 18:05
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How to open Atom editor from command line in OS X?
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If you get "File exists" and the Atom command still dose not work just delete it and type the command over again.
– Anders
Mar 14 '14 at 9:34
1
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Writing a new line to file in PHP (line feed)
...ased operating systems use "\n". You should stick to one convention (I'd chose "\n") and open your file in binary mode (fopen should get "wb", not "w").
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How to stop Flask from initialising twice in Debug Mode? [duplicate]
..., you can check for the value of WERKZEUG_RUN_MAIN in the environment:
if os.environ.get("WERKZEUG_RUN_MAIN") == "true":
# The reloader has already run - do what you want to do here
However, the condition is a bit more convoluted when you want the behavior to happen any time except in the loa...
How to download Xcode DMG or XIP file?
...latest revision is kept in the list.)
Xcode 12
12.2 beta
12 (Requires macOS 10.15.4 or later) (Latest as of 17-Sept-2020)
Xcode 11
11.7 (Latest as of Sept 02 2020)
11.6
11.5
11.4.1 (Requires macOS 10.15.2 or later)
11.3.1
11.2.1
11.1
11 (Requires macOS 10.14.4 or later)
Xcode 10 (unsu...