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How do I update if exists, insert if not (AKA “upsert” or “merge”) in MySQL?
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@blub: If you create a unique key on geb and topic it will work (ALTER TABLE table ADD UNIQUE geb_by_topic (geb, topic)).
– chaos
Aug 2 '09 at 13:43
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Why is i++ not atomic?
...crement operation atomic; it involves synchronization at both the software and hardware levels that need not be present in an ordinary increment.
You could make the argument that i++ should have been designed and documented as specifically performing an atomic increment, so that a non-atomic increm...
How to generate string of a certain length to insert into a file to meet a file size criteria?
...utomatically generate the files. I know the size of each file, ex. 100KB, and how many files to generate. What I need help with is how to generate a string less than or equal to the required file size.
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Methods inside enum in C#
...his implementation is not native in the language, the syntax (construction and usage) is pretty close to languages that implement enums natively better than C# (Kotlin for example).
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Can I do a synchronous request with volley?
...t(); // this will block
} catch (InterruptedException e) {
// exception handling
} catch (ExecutionException e) {
// exception handling
}
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What is the use of a private static variable in Java?
...I am also aware that static members are shared by all instances of a class and are not reallocated in each instance.
19 Ans...
What size should TabBar images be?
...of the tab into the image—you're going to have pretty poor accessibility and localization results like that.
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Guards vs. if-then-else vs. cases in Haskell
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From a technical standpoint, all three versions are equivalent.
That being said, my rule of thumb for styles is that if you can read it as if it was English (read | as "when", | otherwise as "otherwise" and = as "is" or "be"), you're probably ...
MySQL DISTINCT on a GROUP_CONCAT()
...n a string like:
test1 test2 test3 test1 test3 test4
(notice that test1 and test3 are duplicated) while the OP wants to return this string:
test1 test2 test3 test4
the problem here is that the string "test1 test3" is duplicated and is inserted only once, but all of the others are distinct to e...
Method to Add new or update existing item in Dictionary
... indexer setters of both classes call this.Insert(key, value, add: false); and the add parameter is responsible for throwing an exception, when inserting a duplicate key. So the behavior is the same for both classes.
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