大约有 12,000 项符合查询结果（耗时：0.0333秒） [XML]
IN vs OR in the SQL WHERE Clause
... you want to know the performance difference between the following:
WHERE foo IN ('a', 'b', 'c')
WHERE foo = 'a' OR foo = 'b' OR foo = 'c'
According to the manual for MySQL if the values are constant IN sorts the list and then uses a binary search. I would imagine that OR evaluates them one by on...
Is there something like Annotation Inheritance in java?
...value = {ElementType.TYPE})
@Vehicle
public @interface Car {
}
@Car
class Foo {
}
You can then check if a class is annotated with Vehicle using Spring's AnnotationUtils:
Vehicle vehicleAnnotation = AnnotationUtils.findAnnotation (Foo.class, Vehicle.class);
boolean isAnnotated = vehicleAnnotation...
How to compute the similarity between two text documents?
...swered Jan 17 '12 at 15:54
Fred FooFred Foo
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Only using @JsonIgnore during serialization, but not deserialization
...oreProperties(allowSetters = true, value = {"bar"})
class Pojo{
String foo;
String bar;
}
Both foo and bar are populated in the object, but only foo is written into a response body.
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...
C++ catching all exceptions
...h(...) is meant to be used in conjunction with throw; basically:
try{
foo = new Foo;
bar = new Bar;
}
catch(...) // will catch all possible errors thrown.
{
delete foo;
delete bar;
throw; // throw the same error again to be handled somewhere else
}
This is the pr...
ORA-00979 not a group by expression
...le to understand why this happens: Imagine you have a database like this:
FOO BAR
0 A
0 B
and you run SELECT * FROM table GROUP BY foo. This means the database must return a single row as result with the first column 0 to fulfill the GROUP BY but there are now two values of bar to chose from....
How do I check if a directory exists? “is_dir”, “file_exists” or both?
...name is taken, you should check both. There might be a regular file named 'foo', which would prevent you from creating a directory name 'foo'.
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Run a batch file with Windows task scheduler
...
This fixed a scheduled 'foo.cmd' task for me on Windows Server 2012. With 'Start in' set to 'C:\Foo\' the task failed with exit code error 0x8007001, but with 'Start in' set to 'C:\Foo' the task ran fine.
– Aaron
...
What does the function then() mean in JavaScript?
... resolve, reject)
})
}
Promise.all([
fetchPromised("http://backend/foo.txt", 500),
fetchPromised("http://backend/bar.txt", 500),
fetchPromised("http://backend/baz.txt", 500)
]).then((data) => {
let [ foo, bar, baz ] = data
console.log(`success: foo=${foo} bar=${bar} baz=${...
Serialize form data to JSON [duplicate]
... @dev.pus: You might need to handle it in the [{"name":"username","value":"foo"}] format. Otherwise, you cannot handle multiple elements with the same name.
– Matthew Schinckel
Apr 26 '13 at 8:19
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