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Adding :default => true to boolean in existing Rails column
...dding a default boolean value to an existing column. So I tried the change_column suggestion but I mustn't be doing it right.
...
Select first row in each GROUP BY group?
... SELECT p.id,
p.customer,
p.total,
ROW_NUMBER() OVER(PARTITION BY p.customer
ORDER BY p.total DESC) AS rk
FROM PURCHASES p)
SELECT s.*
FROM summary s
WHERE s.rk = 1
Supported by any database:
But you need to add logic...
How does zip(*[iter(s)]*n) work in Python?
... ^
And since you ask for a more verbose code sample:
chunk_size = 3
L = [1,2,3,4,5,6,7,8,9]
# iterate over L in steps of 3
for start in range(0,len(L),chunk_size): # xrange() in 2.x; range() in 3.x
end = start + chunk_size
print L[start:end] # three-item chunks
Following ...
Why should I prefer to use member initialization lists?
...t constructor. Consider:
class A
{
public:
A() { x = 0; }
A(int x_) { x = x_; }
int x;
};
class B
{
public:
B()
{
a.x = 3;
}
private:
A a;
};
In this case, the constructor for B will call the default constructor for A, and then initialize a.x to 3. A better ...
The name 'model' does not exist in current context in MVC3
... key="webpages:Version" value="3.0.0.0" />
– Simon_Weaver
May 26 '14 at 22:04
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场景样式（HarmonyStyleKit）使用指导 · App Inventor 2 中文网
...，将同名事件的处理合并到一个事件积木中。
when 按钮_主题.Click() {
标签1.Text = HarmonyStyleKit1.BuildSceneTheme("compact", "service-center", "#2196F3")
}
案例二：应用主题到当前表单
when 按钮_应用.Click() {
HarmonyStyleKit1.App...
How to raise a ValueError?
...trates how to raise a ValueError the way you want. By-the-way, I think find_last(), find_last_index(), or something simlar would be a more descriptive name for this function. Adding to the possible confusion is the fact that Python already has a container object method named __contains__() that does...
Read url to string in few lines of java code
... Scanner(new URL(requestURL).openStream(),
StandardCharsets.UTF_8.toString()))
{
scanner.useDelimiter("\\A");
return scanner.hasNext() ? scanner.next() : "";
}
}
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How to test equality of Swift enums with associated values
...problem @MichaelWaterfall mentioned by replacing default with case (.Name, _): return false; case(.Number, _): return false.
– Kazmasaurus
Aug 5 '15 at 23:30
25
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How to fix the uninitialized constant Rake::DSL problem on Heroku?
...
Put this in your Rakefile above require 'rake':
require 'rake/dsl_definition'
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