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Adding a new SQL column with a default value
...
Try this:
ALTER TABLE table1 ADD COLUMN foo INT DEFAULT 0;
From the documentation that you linked to:
ALTER [ONLINE | OFFLINE] [IGNORE] TABLE tbl_name
alter_specification [, alter_specification] ...
alter_specification:
...
ADD [COLUMN] (col_name c...
javascript: pause setTimeout();
...Usage: new Timer(Function, Number, arg1, arg2, arg3...)
function callback(foo, bar) {
console.log(foo); // "foo"
console.log(bar); // "bar"
}
var timer = new Timer(callback, 1000, "foo", "bar");
timer.pause();
document.onclick = timer.resume;
...
Why do we need C Unions?
...efined behavior should be removed. It is, in fact, defined behavior. See footnote 82 of the C99 standard: If the member used to access the contents of a union object is not the same as the member last used to store a value in the object, the appropriate part of the object representation of the val...
Require either of two arguments using argparse
...exclusion (at least for the second part of your question).
This way, only foo or bar will be accepted, not both.
import argparse
parser = argparse.ArgumentParser()
group = parser.add_mutually_exclusive_group(required=True)
group.add_argument('--foo',action=.....)
group.add_ar...
Check if a given key already exists in a dictionary
...stead. It sounds like it will do everything you want.
>>> d = {'foo':'bar'}
>>> q = d.setdefault('foo','baz') #Do not override the existing key
>>> print q #The value takes what was originally in the dictionary
bar
>>> print d
{'foo': 'bar'}
>>> r = d.s...
How do I add the contents of an iterable to a set?
...
You can add elements of a list to a set like this:
>>> foo = set(range(0, 4))
>>> foo
set([0, 1, 2, 3])
>>> foo.update(range(2, 6))
>>> foo
set([0, 1, 2, 3, 4, 5])
share
...
How to execute a raw update sql with dynamic binding in rails
...n say this:
ActiveRecord::Base.connection.execute(<<-EOQ)
UPDATE foo
SET bar = #{ActiveRecord::Base.connection.quote(baz)}
EOQ
Note if you're in a Rails migration or an ActiveRecord object you can shorten that to:
connection.execute(<<-EOQ)
UPDATE foo
SET bar = #{co...
Does Python have an ordered set?
...te a dict, then simply ask for the keys() back.
>>> keywords = ['foo', 'bar', 'bar', 'foo', 'baz', 'foo']
>>> list(dict.fromkeys(keywords))
['foo', 'bar', 'baz']
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|
improve...
What is reflection and why is it useful?
...give you a code example of this in Java (imagine the object in question is foo) :
Method method = foo.getClass().getMethod("doSomething", null);
method.invoke(foo, null);
One very common use case in Java is the usage with annotations. JUnit 4, for example, will use reflection to look through your...
How to reference constants in EL?
...ported via ImportHandler#importClass() and be available as ${YourConstants.FOO}.
Note that all java.lang.* classes are already implicitly imported and available like so ${Boolean.TRUE} and ${Integer.MAX_VALUE}. This only requires a more recent Java EE 7 container server as early versions had bugs i...