大约有 47,000 项符合查询结果（耗时：0.0559秒） [XML]
How dangerous is it to compare floating point values?
...nt the actual result. An easy example where you can see this is adding x = 0x1fffffe and y = 1 as floats. Here, x has 24 bits of precision in the mantissa (ok) and y has just 1 bit, but when you add them, their bits are not in overlapping places, and the result would need 25 bits of precision. Inste...
How do you read CSS rule values with JavaScript?
...(className) {
var cssText = "";
var classes = document.styleSheets[0].rules || document.styleSheets[0].cssRules;
for (var x = 0; x < classes.length; x++) {
if (classes[x].selectorText == className) {
cssText += classes[x].cssText || classes[x].style.cssText...
Count with IF condition in MySQL query
...ELECT
ccc_news . * ,
SUM(if(ccc_news_comments.id = 'approved', 1, 0)) AS comments
FROM
ccc_news
LEFT JOIN
ccc_news_comments
ON
ccc_news_comments.news_id = ccc_news.news_id
WHERE
`ccc_news`.`category` = 'news_layer2'
AND `ccc_news`.`status` = 'Active'
GROU...
Java variable number or arguments for a method
...
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edited Oct 20 '17 at 1:43
ErikE
41.4k1717 gold badges130130 silver badges172172 bronze badges
...
How to install a specific version of a ruby gem?
...
answered Jun 10 '13 at 14:37
mjsmjs
54.3k2424 gold badges7979 silver badges111111 bronze badges
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postgresql COUNT(DISTINCT …) very slow
...
40
holy queries batman! This sped up my postgres count distinct from 190s to 4.5 whoa!
– rogerdpack
Nov ...
Adjust UILabel height to text
...e just put this in a playground and it works for me.
Updated for Swift 4.0
import UIKit
func heightForView(text:String, font:UIFont, width:CGFloat) -> CGFloat{
let label:UILabel = UILabel(frame: CGRectMake(0, 0, width, CGFloat.greatestFiniteMagnitude))
label.numberOfLines = 0
lab...
MySQL connection not working: 2002 No such file or directory
...
answered Nov 4 '09 at 21:28
Alec GorgeAlec Gorge
15.3k99 gold badges5454 silver badges6969 bronze badges
...
Creating JS object with Object.create(null)?
...
200
They are not equivalent. {}.constructor.prototype == Object.prototype while Object.create(null)...
Which MySQL data type to use for storing boolean values
...
For MySQL 5.0.3 and higher, you can use BIT. The manual says:
As of MySQL 5.0.3, the BIT data type is used to store bit-field
values. A type of BIT(M) enables storage of M-bit values. M can range
from 1 to 64.
Otherwise, according to t...