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String concatenation in MySQL
...most DBMSs use of + or || for concatenation. It uses the CONCAT function:
SELECT CONCAT(first_name, " ", last_name) AS Name FROM test.student
As @eggyal pointed out in comments, you can enable string concatenation with the || operator in MySQL by setting the PIPES_AS_CONCAT SQL mode.
...
Why does installing Nokogiri on Mac OS fail with libiconv is missing?
...ed to install xCode command tools to allow you to install libiconv.
xcode-select --install
then install a newer version of libiconv
brew install libiconv
then install your gem
gem install nokogiri -- --with-iconv-dir=/usr/local/Cellar/libiconv/1.14
...
How to enable NSZombie in Xcode?
...cheme".
To edit the scheme and turn on zombies:
In the "Product" menu, select "Edit Scheme".
Go to the "Run Foo.app" stage in the left panel, and the "Arguments" tab on the right.
Add NSZombieEnabled to the "Environment Variables" section and set the value to YES, as you could in Xcode 3.
In...
Update Item to Revision vs Revert to Revision
...ision will undo all changes in your working copy which were made after the selected revision (in your example rev. 96,97,98,99,100)
Your working copy is now in modified state.
The file content of both scenarions is same, however in first case you have an unmodified working copy and you cannot comm...
How to use a variable to specify column name in ggplot
... on the value if the name is not found. This is actually what happens with select, but not with group_by ... It's possible to hack around it but not obvious. If it's important to you I think it would deserve its own question.
– Moody_Mudskipper
Aug 20 '19 at 23...
Possible to iterate backwards through a foreach?
...inq can help you.
A Linq extension method using anonymous types with Linq Select to provide a sorting key for Linq OrderByDescending;
public static IEnumerable<T> Invert<T>(this IEnumerable<T> source)
{
var transform = source.Select(
(o, i) => new
...
Wi-Fi 是什么的缩写 - 程序人生、谈天论地 - 清泛IT论坛，有思想、有深度
请对照上图自测。如果你是 Level 0，阅读本文前建议先搜索并查看相关资料学习 Wi-Fi 的基本概念，本文将不涉及定义或技术上的解释。Wi-Fi 是 Wireless Fidelity 吗一天和客户闲聊，我随口问了一句，Wi-Fi 是什么的缩写？客户是个美...
Delete all the queues from RabbitMQ?
...oto Policies tab(on the right side)
Add Policy
Fill Fields
Virtual Host: Select
Name: Expire All Policies(Delete Later)
Pattern: .*
Apply to: Queues
Definition: expires with value 1 (change type from String to Number)
Save
Checkout Queues tab again
All Queues must be deleted
And don't forget remo...
MySQL: Order by field size/length
...
SELECT * FROM TEST ORDER BY LENGTH(description) DESC;
The LENGTH function gives the length of string in bytes. If you want to count (multi-byte) characters, use the CHAR_LENGTH function instead:
SELECT * FROM TEST ORDER BY...
Eclipse JPA Project Change Event Handler (waiting)
...ould probably try to open a discussion on the amount of included and not deselectable features/project included in a release. And it should maybe discuss ways to disable packaged features (such as JPT).
– mwhs
Mar 31 '14 at 8:38
...