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How to map a composite key with JPA and Hibernate?
...y the specification also applies. So here they are:
2.1.4 Primary Keys and Entity Identity
...
A composite primary key must
correspond to either a single
persistent field or property or to a
set of such fields or properties as
described below. A primary key class
must be defi...
git rebase without changing commit timestamps
...-committer-date-is-author-date option seems to leave the author timestamp, and set the committer timestamp to be the same as the original author timestamp, which is what the OP Olivier Verdier wanted.
I found the last commit with the correct date and did:
git rebase --committer-date-is-author-dat...
Reduce left and right margins in matplotlib plot
...
If you have multiple subplots and want to save each of them, you can use this with fig.savefig() too. (plt.savefig() will not work in that case.)
– Abhranil Das
Apr 21 '13 at 12:07
...
Is < faster than
...n two machine instructions:
A test or cmp instruction, which sets EFLAGS
And a Jcc (jump) instruction, depending on the comparison type (and code layout):
jne - Jump if not equal --> ZF = 0
jz - Jump if zero (equal) --> ZF = 1
jg - Jump if greater --> ZF = 0 and SF = OF
(etc...)
Exa...
Python String and Integer concatenation [duplicate]
...ed in this answer (backticks) is deprecated in later versions of Python 2, and removed in Python 3. Use the str() function instead.
You can use :
string = 'string'
for i in range(11):
string +=`i`
print string
It will print string012345678910.
To get string0, string1 ..... string10 you can use...
Standard alternative to GCC's ##__VA_ARGS__ trick?
...preprocessor features; you must use some extension to the language. clang and icc have adopted this GCC extension, but MSVC has not.
Back in 2001 I wrote up the GCC extension for standardization (and the related extension that lets you use a name other than __VA_ARGS__ for the rest-parameter) in ...
How do the post increment (i++) and pre increment (++i) operators work in Java?
...=>
i=5 + 7 + 8; (a=8)
The main point is that ++a increments the value and immediately returns it.
a++ also increments the value (in the background) but returns unchanged value of the variable - what looks like it is executed later.
...
What is the best way to ensure only one instance of a Bash script is running? [duplicate]
... a lockfile approach. If you acquire the lock, proceed else show a message and exit.
As an example:
[Terminal #1] $ lockfile -r 0 /tmp/the.lock
[Terminal #1] $
[Terminal #2] $ lockfile -r 0 /tmp/the.lock
[Terminal #2] lockfile: Sorry, giving up on "/tmp/the.lock"
[Terminal #1] $ rm -f /tmp/the....
How do I grant myself admin access to a local SQL Server instance?
... to access sql server's data by copying the data files to another machine (and then copying back if needed), so your only way around this is to limit administrative permissions only to the ones who deserve it..
– yoel halb
Oct 11 '12 at 20:18
...
How important is the order of columns in indexes?
... Also keep in mind, suppose your Index is like the picture above, and your query filters on column1 and column2, but column2 is more unique and what you really want to filter on is actually column2, then its more beneficial to just have a index where column 2 is first. This may seem counte...