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Select DISTINCT individual columns in django?
... can do the following to get the names of distinct categories:
q = ProductOrder.objects.values('Category').distinct()
print q.query # See for yourself.
# The query would look something like
# SELECT DISTINCT "app_productorder"."category" FROM "app_productorder"
There are a couple of things to re...
Specifically, what's dangerous about casting the result of malloc?
.... That's going to be either a sign extension or zero extension of the low order 32-bits that it has been told malloc "returns" by omitting the prototype. Since int is signed I think the conversion will be sign extension, which will in this case convert the value to zero. With a return value of 0x...
Serialize Class containing Dictionary member
...aContractSerializer is that it serializes and deserializes in alphabetical order so if you try to deserialize something in the wrong order it will fail silently with null properties in your object
– superjugy
Mar 30 '18 at 16:09
...
Default string initialization: NULL or Empty? [closed]
...ccount for other philosophies. There, it's the job of your code to impose order on chaos. Part of that order is knowing when an empty string should mean String.Empty and when it should mean null.
(Just to make sure I wasn't talking out of my ass, I just searched our codebase for `String.IsNullOrE...
Go build: “Cannot find package” (even though GOPATH is set)
...ce isn't found there—it searches for src/widget inside each workspace in order.
(a "workspace" is a path entry in your GOPATH: that variable can reference multiple paths for your 'src, bin, pkg' to be)
(Original answer)
You also should set GOPATH to ~/go, not GOROOT, as illustrated in "How to Wr...
What is BSON and exactly how is it different from JSON?
...pes such as Date and binary which are not supported in JSON also provide ordered fields in order for it to be efficient for encoding and decoding within different languages.
In other word we can say BSON is just binary JSON ( a superset of JSON with some more data types, most importantl...
Break parallel.foreach?
...reason caused the break are processed. What about a Parallel.ForEach where order of the items does not necessarily have to be the order in which they are processed? Is it guaranteed as well that all items in an IEnumerable<...> before the one that invokes state.Break() are being processed and ...
How to simulate Android killing my process
...tyB onCreate WITHOUT savedInstance
ActivityB onStart
ActivityA onStop (the order is like this, it is stopped after new one is started)
<go settings>
ActivityB onStop
<disable a permission>
//Application is killed, but onDestroy methods are not called.
//Android does not call onDestroy me...
SQL Add foreign key to existing column
...
MySQL / SQL Server / Oracle / MS Access:
ALTER TABLE Orders
ADD FOREIGN KEY (P_Id)
REFERENCES Persons(P_Id)
To allow naming of a FOREIGN KEY constraint, and for defining a FOREIGN KEY constraint on multiple columns, use the following SQL syntax:
MySQL / SQL Server / Oracle /...
getenv() vs. $_ENV in PHP
...$_ENV is not always populated due to different configurations of variables_order so it's best if you avoid $_ENV if you don't control the server configuration.
So, for the most portable PHP code:
Use getenv.
Use the correct case for the environment variable name.
...