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How to select rows with no matching entry in another table?
...application and I've discovered that, joy of joys, even though values from one table are being used in the style of foreign keys, there's no foreign key constraints on the tables.
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How to create circle with Bézier curves?
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Yeah, since this one has a max deviation of +0.027% and a min deviation of -0 vs the true circle. It's only ever bigger than the real circle the better improved approximation is done by moving C in by half of 0.027%. If you want the midpoints...
Named regular expression group “(?Pregexp)”: what does “P” stand for?
In Python, the (?P<group_name>…) syntax allows one to refer to the matched string through its name:
3 Answers
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html select option separator
...ser would be confronted with rows of dashes and would have to examine each one to find out what was behind it.
– Quentin
May 22 '09 at 18:41
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What is difference between CrudRepository and JpaRepository interfaces in Spring Data JPA?
...context and deleting records in a batch.
Because of the inheritance mentioned above, JpaRepository will have all the functions of CrudRepository and PagingAndSortingRepository. So if you don't need the repository to have the functions provided by JpaRepository and PagingAndSortingRepository , use...
Difference between staticmethod and classmethod
...at is the difference between a function decorated with @staticmethod and one decorated with @classmethod ?
27 Answers
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++someVariable vs. someVariable++ in JavaScript
...value of the expression is the original value"
Now when used as a standalone statement, they mean the same thing:
x++;
++x;
The difference comes when you use the value of the expression elsewhere. For example:
x = 0;
y = array[x++]; // This will get array[0]
x = 0;
y = array[++x]; // This wil...
How do you rename a MongoDB database?
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This is just to accomplish a rename of a single database in a standalone mongod instance. For replica sets the above would need to be done on every replica node, plus on each node every single oplog entry that refers this database would have to be somehow invalidated or rewritten, and then if ...
MySQL: Insert record if not exists in table
...022') AS tmp - but that will only work if table_listnames already contains one or more rows. I doubt the speed is any different though, so it's probably not a concern.
– Mike
Jul 2 '10 at 10:54
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Is there an equivalent for the Zip function in Clojure Core or Contrib?
...ure and other Lisps have good support for variable arity functions; map is one of them and can be used for "tupling" in a manner similar to Haskell's
zipWith (\x y -> (x, y))
The idiomatic way to build a "tuple" in Clojure is to construct a short vector, as displayed above.
(Just for complete...