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#1071 - Specified key was too long; max key length is 1000 bytes
...d to storage or the range of values allowed for the column. INT is always 4 bytes, and it always allows values from -2147483648 to 2147483647. The numeric argument is about padding values during display, which has no effect unless you use the ZEROFILL option.
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数据结构与本地数据库 04：从打包 JSON 读取知识卡片 · App Inventor 2 中文网
... 数据结构与本地数据库 04：从打包 JSON 读取知识卡片 课程首页 · 全部知识课程 · 返回专题主页
这课解决什么
先预测，再运行
开始实战
新增或调整的...
What is memoization and how can I use it in Python?
...Memoize(factorial)
A feature known as "decorators" was added in Python 2.4 which allow you to now simply write the following to accomplish the same thing:
@Memoize
def factorial(k):
if k < 2: return 1
return k * factorial(k - 1)
The Python Decorator Library has a similar decorator ca...
How do I get current date/time on the Windows command line in a suitable format for usage in a file/
... with using date . See @npocmaka's https://stackoverflow.com/a/19799236/8479
28 Answers
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How to encrypt/decrypt data in php?
...CBC which has a fixed block size of 16 bytes and a key size of either 16, 24 or 32 bytes.
Encryption key
A good encryption key is a binary blob that's generated from a reliable random number generator. The following example would be recommended (>= 5.3):
$key_size = 32; // 256 bits
$encryption...
How to initialize an array in one step using Ruby?
....8.7+ to create arrays; for example:
array = 1.step(17,3).to_a
#=> [1, 4, 7, 10, 13, 16]
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AJAX POST and Plus Sign ( + ) — How to Encode?
...orrect
escape(text); // %u0100
// correct
encodeURIComponent(text); // "%C4%80"
Note: "%C4%80" is equivalent to: escape('\xc4\x80')
Which is the byte sequence (\xc4\x80) that represents Ā in UTF-8. So if you use encodeURIComponent() your server side must know that it is receiving UTF-8. Otherwi...
MongoDB数据导出导入工具：mongoexport,mongoimport - 大数据 & AI - 清泛...
...个students集合，集合中数据如下：
> db.students.find()
{ "_id" : ObjectId("5031143350f2481577ea81e5"), "classid" : 1, "age" : 20, "name" : "kobe" }
{ "_id" : ObjectId("5031144a50f2481577ea81e6"), "classid" : 1, "age" : 23, "name" : "nash" }
{ "_id" : ObjectId("5031145a50f2481577ea81...
Reference: What is variable scope, which variables are accessible from where and what are “undefined
... scope.
Example:
<?php
$foo = 'bar';
function myFunc() {
$baz = 42;
}
$foo is in the global scope, $baz is in a local scope inside myFunc. Only code inside myFunc has access to $baz. Only code outside myFunc has access to $foo. Neither has access to the other:
<?php
$foo = 'bar';
...
How do I best silence a warning about unused variables?
...e.
– Tobias Langner
Sep 29 '09 at 9:41
18
This is how Q_UNUSED is implemented in principle.
...