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Flask SQLAlchemy query, specify column nam>me m>s
...(it selects all columns by default)? I know how to do this with the sqlalchm>me m>y session: session.query(self.col1) , but how do I do it with with models? I can't do Som>me m>Model.query() . Is there a way?
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How can I maintain fragm>me m>nt state when added to the back stack?
I've written up a dummy activity that switches between two fragm>me m>nts. When you go from Fragm>me m>ntA to Fragm>me m>ntB, Fragm>me m>ntA gets added to the back stack. However, when I return to Fragm>me m>ntA (by pressing back), a totally new Fragm>me m>ntA is created and the state it was in is lost. I get the feeling I'm ...
Difference between Docum>me m>nt-based and Key/Value-based databases?
... explanation.
Data model: more than key-value stores
Although there is som>me m> debate on the correct nam>me m> for databases such as Cassandra, I'd like to call them column-family stores. Although key-value pairs are an essential part of Cassandra, it's not limited to just that. It allows you to nest key-...
How do you represent a JSON array of strings?
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I'll elaborate a bit more on ChrisR awesom>me m> answer and bring images from his awesom>me m> reference.
A valid JSON always starts with either curly braces { or square brackets [, nothing else.
{ will start an object:
{ "key": value, "another key": value }
Hint: although...
Why does substring slicing with index out of range work?
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You're correct! 'example'[3:4] and 'example'[3] are fundam>me m>ntally different, and slicing outside the bounds of a sequence (at least for built-ins) doesn't cause an error.
It might be surprising at first, but it makes sense when you think about it. Indexing returns a single item, ...
error: writable atomic property cannot pair a synthesized setter/getter with a user defined setter/g
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I had the sam>me m> problem and after doing a bit of research, here is my conclusion about this issue:
The compiler warns you about a @property that you declared as atomic (i.e. by omitting the nonatomic keyword), yet you provide an incomple...
Unable to forward search Bash history similarly as with CTRL-r
...s forward through the history.
The problem with Ctrl-S however is that som>me m>tim>me m>s collides with XON/XOFF flow control (in Konsole for instance). The searching is a readline feature however, and you should be able to bind it to som>me m> other key. Update: Simpler and better is just to disable XON/XOFF b...
How do I install a NuGet package .nupkg file locally?
I have som>me m> .nupkg files from a C# book. How can I install them?
8 Answers
8
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Should functions return null or an empty object?
... returning a null will result in a null exception if you attempt to access m>me m>mbers in the object, which can be useful for highlighting buggy code - attempting to access a m>me m>mber of nothing makes no sense. Accessing m>me m>mbers of an empty object will not fail m>me m>aning bugs can go undiscovered.
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