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Get top n records for each group of grouped results
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Here is one way to do this, using UNION ALL (See SQL Fiddle with Demo). This works with two groups, if you have more than two groups, then you would need to specify the group number and add queries for each group:
(
select *
from mytable
where `group` = 1
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Difference between 'struct' and 'typedef struct' in C++?
...struct Foo x;
Any time you want to refer to a Foo, you'd always have to call it a struct Foo. This gets annoying fast, so you can add a typedef:
struct Foo { ... };
typedef struct Foo Foo;
Now struct Foo (in the tag namespace) and just plain Foo (in the ordinary identifier namespace) both refe...
How does the Comma Operator work
...t", "xor";
Notice that due to operator precedence, the code is (intentionally!) identical to
(((keywords = "and"), "or"), "not"), "xor";
That is, the first operator called is keywords.operator =("and") which returns a proxy object on which the remaining operator,s are invoked:
keywords.operato...
optional local variables in rails partial templates: how do I get out of the (defined? foo) mess?
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Though I really like the compact syntax of hgimenez's suggestion (above), this approach has the advantage of being very clear re: what's going on. (Still has the downside of not letting you pass nil as a value for the local)
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Bash command to sum a column of numbers [duplicate]
...mn of numbers. I just want a quick one liner that will do something essentially like this:
10 Answers
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How different is Objective-C from C++? [closed]
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Short list of some of the major differences:
C++ allows multiple inheritance, Objective-C doesn't.
Unlike C++, Objective-C allows method parameters to be named and the method signature includes only the names and types of the parameters and return type (see bbum's and Chuck...
How to pipe stdout while keeping it on screen ? (and not to a output file)
... /dev/tty | tee -a other.log | grep -i 'foo' >> foo.log to 1) get it all to the console, 2) get it all appended to another file, 3) get the foo lines to a different file.
– Jesse Chisholm
Mar 9 '17 at 16:05
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How to validate an e-mail address in swift?
...s quite funny that ............ as well as (1) the regex being utterly, totally incorrect (2) the regex (even within the context of what it's trying to do) has major errors (3) the Swift is wrong (4) even setting that aside, the style is totally wrong (5) not that it matters given all the rest but i...
How do I write a bash script to restart a process if it dies?
...crashing on your hands. The sleep 1 takes away the strain from that.
Now all you need to do is start this bash script (asynchronously, probably), and it will monitor myserver and restart it as necessary. If you want to start the monitor on boot (making the server "survive" reboots), you can sched...
GNU Makefile rule generating a few targets from a single source file
I am attempting to do the following. There is a program, call it foo-bin , that takes in a single input file and generates two output files. A dumb Makefile rule for this would be:
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