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Rails: select unique values from a column
...rks only on "top level" queries, like above. Doesn't work on collection prom>x m>ies ("has_many" relations, for em>x m>ample).
Address.distinct.pluck(:city) # => ['Moscow']
user.addresses.distinct.pluck(:city) # => ['Moscow', 'Moscow', 'Moscow']
In this case, deduplicate after the query
user.address...
Simple em>x m>planation of clojure protocols
...ols and what problem they are supposed to solve. Does anyone have a clear em>x m>planation of the whats and whys of clojure protocols?
...
Python: using a recursive algorithm as a generator
...
def getPermutations(string, prefim>x m>=""):
if len(string) == 1:
yield prefim>x m> + string
else:
for i in m>x m>range(len(string)):
for perm in getPermutations(string[:i] + string[i+1:], prefim>x m>+string[i]):
yield perm
...
Scala 2.8 breakOut
...lable.
About breakOut
So, what's the purpose of breakOut? Consider the em>x m>ample given for the question, You take a list of strings, transform each string into a tuple (Int, String), and then produce a Map out of it. The most obvious way to do that would produce an intermediary List[(Int, String)] ...
Difference between char* and const char*?
...to (https://msdn.microsoft.com/en-us/library/vstudio/whkd4k6a(v=vs.100).aspm>x m>, see "Em>x m>amples"). In this case, the const specifier applies to char, not the asterisk.
According to the MSDN page and http://en.cppreference.com/w/cpp/language/declarations, the const before the * is part of the decl-speci...
Convert pem key to ssh-rsa format
...eygen):
-m key_format Specify a key format for the -i (import) or -e (em>x m>port) conversion options. The supported key formats are: “RFC4716” (RFC 4716/SSH2 public or private key), “PKCS8” (PEM PKCS8 public key) or “PEM” (PEM public key). The default conversion format is “RFC4716”...
Why am I getting an Em>x m>ception with the message “Invalid setup on a non-virtual (overridable in VB) m
...ile running a test using mock object, MOQ actually creates an in-memory prom>x m>y type which inherits from your "m>X m>mlCupboardAccess" and overrides the behaviors that you have set up in the "SetUp" method. And as you know in C#, you can override something only if it is marked as virtual which isn't the ca...
Difference Between Invoke and DynamicInvoke
...e between Invoke and DynamicInvoke in delegates? Please give me some code em>x m>ample which em>x m>plain difference between that two methods.
...
in entity framework code first, how to use KeyAttribute on multiple columns
...olumn, and specifically, how can I control order of the columns in the indem>x m>? Is it a result of the order of properties in the class?
...
Why does “,,,” == Array(4) in Javascript?
...length of the array to that number. So you can say you have four empty indem>x m>es (same as [,,,]) and the default string representation of arrays is a comma-separated list of its elements:
> ['a','b','c'].toString()
"a,b,c"
How the comparison works is described in section 11.9.3 of the specif...