大约有 19,000 项符合查询结果（耗时：0.0432秒） [XML]
Rails migration: t.references with alternative name?
...n with this:
add_foreign_key :courses, :courses, column: :transferrable_as_id
add_foreign_key :courses, :courses, column: :same_as_id
Update
In Rails 5.1 and above you can add the foreign key in the migration in the create_table block like this:
create_table :courses do |t|
t.string :name
t.ref...
How can I find out the current route in Rails?
... always available in params[:controller] and params[:action]. However, outside of it, if you want to recognize the route, this API is not available anymore. It has now shifted to ActionDispatch::Routing and I haven't tried out the recognize_path on it yet.
– Swanand
...
Android: How to create a Dialog without a title?
I'm trying to generate a custom dialog in Android.
I create my Dialog like this:
25 Answers
...
quick random row selection in Postgres
...
You might want to experiment with OFFSET, as in
SELECT myid FROM mytable OFFSET floor(random()*N) LIMIT 1;
The N is the number of rows in mytable. You may need to first do a SELECT COUNT(*) to figure out the value of N.
Update (by Antony Hatchkins)
You must use floor here:
SELE...
jQuery checkbox checked state changed event
I want an event to fire client side when a checkbox is checked / unchecked:
10 Answers
...
Horizontal ListView in Android?
...lected item at the same spot I clicked. How can I rectify this problem? My idea was to set the ListView with a horizontal scroll. Share your idea?
...
When should I use h:outputLink instead of h:commandLink?
... renders a HTML <a> element with an onclick script which submits a (hidden) POST form and can invoke a managed bean action method. It's also required to be placed inside a <h:form>.
<h:form>
<h:commandLink value="link text" action="destination" />
</h:form>
The ?fa...
How to override the copy/deepcopy operations for a Python object?
...her copy nor deepcopy call the constructor of the object being copied. Consider this example. class Test1(object): def init__(self): print "%s.%s" % (self.__class.__name__, "init") class Test2(Test1): def __copy__(self): new = type(self)() return new t1 = Test1() co...
Use Font Awesome Icon in Placeholder
...lass="form-group">
<input type="text" class="form-control empty" id="iconified" placeholder="&#xF002;"/>
</div>
</form>
With this CSS:
input.empty {
font-family: FontAwesome;
font-style: normal;
font-weight: normal;
text-decoration: inherit;
}
And ...
Why are dashes preferred for CSS selectors / HTML attributes?
In the past I've always used underscores for defining class and id attributes in HTML. Over the last few years I changed over to dashes, mostly to align myself with the trend in the community , not necessarily because it made sense to me.
...