大约有 47,000 项符合查询结果（耗时：0.0690秒） [XML]
postgresql COUNT(DISTINCT …) very slow
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40
holy queries batman! This sped up my postgres count distinct from 190s to 4.5 whoa!
– rogerdpack
Nov ...
What is the difference between “int” and “uint” / “long” and “ulong”?
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230
The primitive data types prefixed with "u" are unsigned versions with the same bit sizes. Effect...
Better techniques for trimming leading zeros in SQL Server?
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SUBSTRING(str_col, PATINDEX('%[^0]%', str_col+'.'), LEN(str_col))
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Read input from console in Ruby?
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230
Are you talking about gets?
puts "Enter A"
a = gets.chomp
puts "Enter B"
b = gets.chomp
c = a.t...
Are members of a C++ struct initialized to 0 by default?
... constructors
struct Snapshot {
int x;
double y;
Snapshot():x(0),y(0) { }
// other ctors / functions...
};
Will initialize both x and y to 0. Note that you can use x(), y() to initialize them disregarding of their type: That's then value initialization, and usually yields a proper...
What is the significance of load factor in HashMap?
...ize and load factor . I went through the Java documentation and it says 0.75f is the initial load factor. But I can't find the actual use of it.
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Android - shadow on text?
...textSize">12sp</item>
<item name="android:shadowColor">#000000</item>
<item name="android:shadowDx">1</item>
<item name="android:shadowDy">1</item>
<item name="android:shadowRadius">1</item>
</style>
And in your layou...
Why is === faster than == in PHP?
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202
Because the equality operator == coerces, or converts, the data type temporarily to see if it...
Generate list of all possible permutations of a string
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70
There are several ways to do this. Common methods use recursion, memoization, or dynamic program...
Get all attributes of an element using jQuery
...:
(function(old) {
$.fn.attr = function() {
if(arguments.length === 0) {
if(this.length === 0) {
return null;
}
var obj = {};
$.each(this[0].attributes, function() {
if(this.specified) {
obj[this.name] = this.value;
}
});
...