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How SID is different from Service name in Oracle tnsnames.ora
...me = alias to an INSTANCE (or many instances). The main purpose of this is if you are running a cluster, the client can say "connect me to SALES.acme.com", the DBA can on the fly change the number of instances which are available to SALES.acme.com requests, or even move SALES.acme.com to a completel...
How to Convert Boolean to String
...in some cases it's not the best solution. The ?: notation is the most simplified code we can come up with in this situation.
– caiosm1005
Jul 14 '13 at 23:39
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Why do most C developers use define instead of const? [duplicate]
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@C. Ross: Consistency. All manifest constants are usually defined with #defines. const is only used to indicate a read-only (access path to a) variable. I know, const in C is just plain broken :-)
– Bart van Ingen Schenau
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Node.js version on the command line? (not the REPL)
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The command line for that is:
node -v
Or
node --version
Note:
If node -v doesn't work, but nodejs -v does, then something's not set up quite right on your system. See this other question for ways to fix it.
shar...
How to pick just one item from a generator?
... would like an item, use
next(g)
(or g.next() in Python 2.5 or below).
If the generator exits, it will raise StopIteration. You can either catch this exception if necessary, or use the default argument to next():
next(g, default_value)
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Inconsistent Accessibility: Parameter type is less accessible than method
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If sounds like the type ACTInterface is not public, but is using the default accessibility of either internal (if it is top-level) or private (if it is nested in another type).
Giving the type the public modifier would fix i...
How do you write multiline strings in Go?
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According to the language specification you can use a raw string literal, where the string is delimited by backticks instead of double quotes.
`line 1
line 2
line 3`
share
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Python Dictionary Comprehension
...n't use them to add keys to an existing dictionary. Also, you have to specify the keys and values, although of course you can specify a dummy value if you like.
>>> d = {n: n**2 for n in range(5)}
>>> print d
{0: 0, 1: 1, 2: 4, 3: 9, 4: 16}
If you want to set them all to True:
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SQL how to increase or decrease one for a int column in one command
...wer the second:
There are several ways to do this. Since you did not specify a database, I will assume MySQL.
INSERT INTO table SET x=1, y=2 ON DUPLICATE KEY UPDATE x=x+1, y=y+2
REPLACE INTO table SET x=1, y=2
They both can handle your question. However, the first syntax allows for more flexi...
delete_all vs destroy_all?
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You are right. If you want to delete the User and all associated objects -> destroy_all
However, if you just want to delete the User without suppressing all associated objects -> delete_all
According to this post : Rails :dependent =...