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SQL “select where not in subquery” returns no results
...efinitely that common_id is not equal to anything from this list, since at least one of the values is NULL.
Suppose we have these data:
common
--
1
3
table1
--
NULL
1
2
LEFT JOIN / IS NULL and NOT EXISTS will return 3, NOT IN will return nothing (since it will always evaluate to either FALSE ...
How does Java Garbage Collection work with Circular References?
...onably current) JVM that uses reference counting, so it seems unlikely (at least to me) that it makes much difference to the original question.
– Jerry Coffin
Dec 15 '09 at 23:28
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How do I uniquely identify computers visiting my web site?
...rg. We observe that the distribution of our finger-
print contains at least 18.1 bits of entropy, meaning that if we pick a
browser at random, at best we expect that only one in 286,777 other
browsers will share its fingerprint. Among browsers that support Flash
or J...
Why is TypedReference behind the scenes? It's so fast and safe… almost magical!
...e performance benefit).
Had they documented it in C#, it would have had at least a couple implications:
Like any feature, it may become a roadblock to new features, especially since this one doesn't really fit in the design of C# and requires weird syntax extensions and special handing of a type by...
Html helper for
...HttpPostedFileBase type of properties, but rather it seems string only. At least it never did accept pdf as as a valid extension.
– Serj Sagan
Feb 13 '13 at 4:38
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How to delete cookies on an ASP.NET website
...es the content from the cookie, the cookie still remains in the browser at least for me
– Nithin Chandran
Oct 11 '17 at 12:09
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Python logging not outputting anything
...ind that after importing logging you need to call logging.basicConfig() at least once. Otherwise you might be badly surprised that child loggers will not print anything. Logging functions on the root logger call it lazily.
– Hubert Grzeskowiak
Aug 28 '19 at 4:2...
PHP - Extracting a property from an array of objects
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The solution depends on the PHP version you are using. At least there are 2 solutions:
First (Newer PHP versions)
As @JosepAlsina said before the best and also shortest solution is to use array_column as following:
$catIds = array_column($objects, 'id');
Notice:
For iterating ...
What is the meaning of #XXX in code comments?
...is not descriptive. In fact, it is very ambiguous. To me, it could mean at least 3 things.
– Ярослав Рахматуллин
Aug 31 '18 at 8:24
2
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How to detect if a stored procedure already exists
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At least if you drop it you know you have to re-add the permissions. If you ran this sql you would not know whether the sproc had the correct permissions or not as you wouldn't know if you had created it or altered it.
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