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How unique is UUID?
...ify something (I'm using it for files uploaded to the server)? As I understand it, it is based off random numbers. However, it seems to me that given enough time, it would eventually repeat it self, just by pure chance. Is there a better system or a pattern of some type to alleviate this issue?
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通信连接组件 · App Inventor 2 中文网
...像的Base64编码及解码方法，便于图像文件的通信传输。此插件仅提供2个函数，使用非常方便，几乎没有学习成本。
属性
无
事件
无
方法
EncodeImage
DecodeImage
MqttClient 拓展
.aix 拓展及demo程序打包下载：
UrsAI2Paho.zip
MQT...
Get size of all tables in database
...S SchemaName,
p.rows,
SUM(a.total_pages) * 8 AS TotalSpaceKB,
CAST(ROUND(((SUM(a.total_pages) * 8) / 1024.00), 2) AS NUMERIC(36, 2)) AS TotalSpaceMB,
SUM(a.used_pages) * 8 AS UsedSpaceKB,
CAST(ROUND(((SUM(a.used_pages) * 8) / 1024.00), 2) AS NUMERIC(36, 2)) AS UsedSpaceMB,
...
How does a PreparedStatement avoid or prevent SQL injection?
...g. But the input parameters will be sent to the database & appropriate cast/conversions will be applied prior to creating an actual SQL statement.
To give you an example, it might try and see if the CAST/Conversion works.
If it works, it could create a final statement out of it.
SELECT * Fr...
How to display gpg key details without importing it?
I have a copy of the postgresql apt repository gpg key and would like to view the details of the gpg key as it comes in the file. Is this possible without importing it into a key ring?
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How to avoid overflow in expr. A * B - C * D
...ere's a work-around that only relies on implementation-defined behavior of casting unsigned integer to signed integer. But this can be expected to work on almost every system today.
(long long)((unsigned long long)A * B - (unsigned long long)C * D)
This casts the inputs to unsigned long long wher...
Swapping two variable value without using third variable
...ks for all integer values (that includes pointers then, with some luck and casting). For the sake of completeness I would like to mention another less powerful algorithm with addition/subtraction:
A = A + B
B = A - B
A = A - B
Here you have to be careful of overflows/underflows, but otherwise it ...
The apk must be signed with the same certificates as the previous version
I had uploaded my app to Google Play (back when it was called Android Market) some time ago.
11 Answers
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How does one generate a random number in Apple's Swift language?
...nteger between 0 and n-1.
let diceRoll = Int(arc4random_uniform(6) + 1)
Cast the result to Int so you don't have to explicitly type your vars as UInt32 (which seems un-Swifty).
share
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improve th...
Covariance, Invariance and Contravariance explained in plain English?
...fferent generics parameters. Their relationships are the reason why we can cast them.
Co and Contra variance are pretty logical things. Language type system forces us to support real life logic. It's easy to understand by example.
Covariance
For instance you want to buy a flower and you have two ...