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How to use NULL or empty string in SQL
...pty string. REASON: if there is ONLY whitespace, a single trim will remove all of it. For example, you don't care whether the comparison fails because what remains is "abc" or " abc".
– ToolmakerSteve
Dec 9 '16 at 20:06
...
How do you run a command for each line of a file?
...teractive processing (sample)
Regarding the OP request: running chmod on all targets listed in file, xargs is the indicated tool. But for some other applications, small amount of files, etc...
Read entire file as command line argument.
If your file is not too big and all files are well named (w...
How to use auto-layout to move other views when a view is hidden?
...iews, even though they don't draw, still participate in Auto Layout and usually retain their frames, leaving other related views in their places.
When removing a view from its superview, all related constraints are also removed from that view hierarchy.
In your case, this likely means:
If you se...
Best practices for storing postal addresses in a database (RDBMS)?
...veal some nice pearls for interpreting and validating addresses internationally. It also has a nice set of administrative areas ( province, state, oblast, etc ) with ISO codes.
Here's the gist of the schema, copied from the module page:
country => Country (always required, 2 character ISO code...
Practical uses for AtomicInteger
I sort of understand that AtomicInteger and other Atomic variables allow concurrent accesses. In what cases is this class typically used though?
...
Mapping many-to-many association table with extra column(s)
...ou don't put any cascade on your relationships, then you must persist/save all the entities. Although only the owning side of the relationship (here, the UserService side) must be initialized, it's also a good practice to make sure both sides are in coherence.
User user = new User();
Service servi...
Grep not as a regular expression
...as grep -F. Direct invocation as fgrep is
deprecated, but is provided to allow historical applications that rely
on them to run unmodified.
For the complete reference, check:
https://www.gnu.org/savannah-checkouts/gnu/grep/manual/grep.html
...
Java multiline string
...
Furthermore, the first version will be automatically concatenated by the compiler, since all the strings are known at compile time. Even if the strings are not known at compile time, it's no slower than StringBuilder or String.format(). The only reason to avoid concatenati...
How do I use vi keys in ipython under *nix?
... ipython --TerminalInteractiveShell.editing_mode=vi
... or to set it globally in the profile configuration (~/.ipython/profile_default/ipython_config.py; create it with ipython profile create if you don't have it) with:
c.TerminalInteractiveShell.editing_mode = 'vi'
...
AngularJS : Initialize service with asynchronous data
...ise;
}
}})
}):
Your controller won't get instantiated before all dependencies are resolved:
app.controller('MainCtrl', function($scope,MyService) {
console.log('Promise is now resolved: '+MyService.doStuff().data)
$scope.data = MyService.doStuff();
});
I've made an example at pl...