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Best practices for SQL varchar column length [closed]
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@Ariel: There are issues and limitations on indexes to consider, too. You can't have a (a,b,c,d) index when all four columns are VARCHAR(255).
– ypercubeᵀᴹ
Nov 28 '11 at 23:30
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Switch case with fallthrough?
I am looking for the correct syntax of the switch statement with fallthrough cases in Bash (ideally case-insensitive).
In PHP I would program it like:
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Facebook Graph API v2.0+ - /me/friends returns empty, or only friends who also use my application
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In v2.0 of the Graph API, calling /me/friends returns the person's friends who also use the app.
In addition, in v2.0, you must request the user_friends permission from each user. user_friends is no longer included by default in every login. Each user...
string.IsNullOrEmpty(string) vs. string.IsNullOrWhiteSpace(string)
... value)
{
if (value == null)
return true;
for (int index = 0; index < value.Length; ++index)
{
if (!char.IsWhiteSpace(value[index]))
return false;
}
return true;
}
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What's the difference between a catalog and a schema in a relational database?
...tem itself.
For example, the optimizer uses catalog information about indexes and other physical storage structures, as well as much other information, to help it decide how to implement user requests. Likewise, the security subsystem uses catalog information about users and security constraint...
Removing an element from an Array (Java) [duplicate]
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ArrayUtils.remove if you want to specify an index, not the value itself
– Line
Dec 10 '18 at 14:43
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show 3 m...
App Inventor 2 拓展参考文档 · App Inventor 2 中文网
...制数据
【数据库】LeanDB 数据库扩展
【数据库】MySQL + php后端数据库
【数据库】MongoDB + php后端数据库
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Simple and fast method to compare images for similarity
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If you want to get an index about the similarity of the two pictures, I suggest you from the metrics the SSIM index. It is more consistent with the human eye. Here is an article about it: Structural Similarity Index
It is implemented in OpenCV to...
What is in your .vimrc? [closed]
Vi and Vim allow for really awesome customization, typically stored inside a .vimrc file. Typical features for a programmer would be syntax highlighting, smart indenting and so on.
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When to use std::size_t?
... in C++. By extension it is also guaranteed to be big enough for any array index so it is a natural type for a loop by index over an array.
If you are just counting up to a number then it may be more natural to use either the type of the variable that holds that number or an int or unsigned int (if...