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SQLAlchemy default DateTime
...rk latency is variable, clients experience slightly different clock drift, and different programming languages occasionally calculate time slightly differently.
SQLAlchemy allows you to do this by passing func.now() or func.current_timestamp() (they are aliases of each other) which tells the DB to c...
Pythonic way of checking if a condition holds for any element of a list
I have a list in Python, and I want to check if any elements are negative. Specman has the has() method for lists which does:
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Unbalanced calls to begin/end appearance transitions for
...the real view controller, but you must have the tab bar controller present and dismiss.
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How do malloc() and free() work?
I want to know how malloc and free work.
13 Answers
13
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What do the following phrases mean in C++: zero-, default- and value-initialization?
...thing to realize is that 'value-initialization' is new with the C++ 2003 standard - it doesn't exist in the original 1998 standard (I think it might be the only difference that's more than a clarification). See Kirill V. Lyadvinsky's answer for the definitions straight from the standard.
See this ...
Why is try {…} finally {…} good; try {…} catch{} bad?
...g the fact that an error occurred. try..finally will run your cleanup code and then the exception will keep going, to be handled by something that knows what to do with it.
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insert a NOT NULL column to an existing table
...Null-able column, then update your table column with valid not null values and finally ALTER column to set NOT NULL constraint:
ALTER TABLE MY_TABLE ADD STAGE INT NULL
GO
UPDATE MY_TABLE SET <a valid not null values for your column>
GO
ALTER TABLE MY_TABLE ALTER COLUMN STAGE INT NOT NULL
GO
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How to get UTC timestamp in Ruby?
... needs additional information to even know that you're dealing with a time and not a number. A Time object solves this problem nicely by representing a point in time and also being explicit about what it is.
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What does “javascript:void(0)” mean?
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The void operator evaluates the given
expression and then returns undefined.
The void operator is often used merely
to obtain the undefined primitive
value, usually using “void(0)” (which
is equivalent to “void 0”). In these
cases, the global variable u...
What's the magic of “-” (a dash) in command-line parameters?
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If you mean the naked - at the end of the tar command, that's common on many commands that want to use a file.
It allows you to specify standard input or output rather than an actual file name.
That's the case for your first and third example. For example, the cdrecord com...