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COUNT(*) vs. COUNT(1) vs. COUNT(pk): which is better? [duplicate]
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Bottom Line
Use either COUNT(field) or COUNT(*), and stick with it consistently, and if your database allows COUNT(tableHere) or COUNT(tableHere.*), use that.
In short, don't use COUNT(1) for anything. It's a one-trick pony, which rarely does what you want, and in those ...
Why can't I initialize non-const static member or static array in class?
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Why I can't initialize static data members in class?
The C++ standard allows only static constant integral or enumeration types to be initialized inside the class. This is the reason a is allowed to be initialized while others are not.
Reference:
C++03 9.4.2 Static data members
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Assignment inside lambda expression in Python
I have a list of objects and I want to remove all objects that are empty except for one, using filter and a lambda expression.
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What is an unsigned char?
...ich gives you at least the 0 to 255 range.
"At least", because the C++ standard only gives the minimum range of values that each numeric type is required to cover. sizeof (char) is required to be 1 (i.e. one byte), but a byte could in theory be for example 32 bits. sizeof would still be report its...
Why isn't `int pow(int base, int exponent)` in the standard C++ libraries?
...ction does not implement the "power" function for anything except float s and double s?
11 Answers
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What are the main disadvantages of Java Server Faces 2.0?
...t basic Web Development (HTML/CSS/JS, server side versus client side, etc) and the basic Java Servlet API (request/response/session, forwarding/redirecting, etc), no serious disadvantages comes to mind. JSF in its current release still needs to get rid of the negative image it gained during the earl...
Mimicking sets in JavaScript?
... you can use the Set object built into ES6. It has very nice capabilities and can be used as is right in your environment.
For many simple things in an ES5 environment, using an Object works very well. If obj is your object and A is a variable that has the value you want to operate on in the set,...
Is Redis just a cache?
I have been reading some Redis docs and trying the tutorial at http://try.redis-db.com/ . So far, I can't see any difference between Redis and caching technologies like Velocity or the Enterprise Library Caching Framework
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Options, Settings, Properties, Configuration, Preferences — when and why?
...In truth it doesn't really matter so long as your expected audience understands what you mean.
The biggest difference is between Properties, which usually affect a component or object, and the others, which affect the whole application.
Following an approximate lead from Visual Studio and other M...
What happens to an open file handle on Linux if the pointed file gets moved or deleted
What happens to an open file handle on Linux if the pointed file meanwhile gets:
7 Answers
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