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How to randomly select rows in SQL?
...* FROM Table1
WHERE (ABS(CAST(
(BINARY_CHECKSUM
(keycol1, NEWID())) as int))
% 100) < 10
https://msdn.microsoft.com/en-us/library/cc441928.aspx
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To ARC or not to ARC? What are the pros and cons? [closed]
...W, make sure to use of Xcode to do the transition (Edit > Refactor > Convert to Objective-C ARC). During the process Xcode would do a lot of validation to make sure your code would work and figure out any codes that violates those designing guidelines.
– ZhangChn
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Cannot use ref or out parameter in lambda expressions
... can be accessed after the method frame is no longer on the stack
Func<int> Example(int p1) {
return () => p1;
}
Another property of captured variables is that changes to the variable are also visible outside the lambda expression. For example the following prints 42
void Example2(in...
Deleting elements from std::set while iterating
...get to the temp. For example, re-write your loop as follows:
std::set<int>::iterator it = numbers.begin();
std::set<int>::iterator tmp;
// iterate through the set and erase all even numbers ...
What does the unary plus operator do?
...erator itself. For example, it can be used to force widening from smaller integral types to int, or ensure that an expression's result is treated as an rvalue and therefore not compatible with a non-const reference parameter. I submit, however, that these uses are better suited to code golf than r...
How to grep and replace
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This touches every file so file times are modified; and converts line endings from CRLF to LF on Windows.
– jww
Oct 25 '17 at 0:21
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Set NOW() as Default Value for datetime datatype?
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it should work for updates too
Answers by Johan & Leonardo involve converting to a timestamp field. Although this is probably ok for the use case presented in the question (storing RegisterDate and LastVisitDate), it is not a universal solution. See datetime vs timestamp question.
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How to compare binary files to check if they are the same?
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I ended up using hexdump to convert the binary files to there hex representation and then opened them in meld / kompare / any other diff tool. Unlike you I was after the differences in the files.
hexdump tmp/Circle_24.png > tmp/hex1.txt
hexdump /tmp...
Can a recursive function be inline?
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First, the inline specification on a function is just a hint. The compiler can (and often does) completely ignore the presence or absence of an inline qualifier. With that said, a compiler can inline a recursive function, much as it can unroll an infinite loop. It simply has to ...
Can table columns with a Foreign Key be NULL?
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Yes, you can enforce the constraint only when the value is not NULL. This can be easily tested with the following example:
CREATE DATABASE t;
USE t;
CREATE TABLE parent (id INT NOT NULL,
PRIMARY KEY (id)
) ENGINE=INNODB;
CREATE TABLE...