大约有 40,000 项符合查询结果（耗时：0.0328秒） [XML]
find() with nil when there are no records
...
Yes, just do:
Challenge.find_by_id(10)
For Rails 4 and 5:
Challenge.find_by(id: 10)
share
|
improve this answer
|
follow
...
How do I check how many options there are in a dropdown menu?
...tList > option').length;
This assumes your <select> list has an ID of mySelectList.
http://api.jquery.com/length/
http://api.jquery.com/children/
http://api.jquery.com/child-selector/
share
|
...
Equivalent of LIMIT and OFFSET for SQL Server?
...antage here is the parameterization of the offset and limit in case you decide to change your paging options (or allow the user to do so).
Note: the @Offset parameter should use one-based indexing for this rather than the normal zero-based indexing.
...
How to write iOS app purely in C
... world we wouldn't have to worry about this, but, remember, this is C.
id autoreleasePool = objc_msgSend(objc_msgSend(objc_getClass("NSAutoreleasePool"), sel_registerName("alloc")), sel_registerName("init"));
// Notice the use of CFSTR here. We cannot use an objective-c string
// liter...
Is it a bad practice to use negative margins in Android?
...
In 2010, @RomainGuy (core Android engineer) stated that negative margins had unspecified behavior.
In 2011, @RomainGuy stated that you can use negative margins on LinearLayout and RelativeLayout.
In 2016, @RomainGuy stated that they have never been offic...
How to post pictures to instagram using API
... such function in the API :( and it feels weird... because they should provide one. I am not sure if there is any other way (except the apps for android and iOS) to upload picture using php. Kindly give me any sort of idea if there is any possibility.
...
PHP - find entry by object property from an array of objects
...this
$item = null;
foreach($array as $struct) {
if ($v == $struct->ID) {
$item = $struct;
break;
}
}
See this question and subsequent answers for more information on the latter - Reference PHP array by multiple indexes
...
How to create a Custom Dialog box in android?
...l
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="80dp"
android:background="#3E80B4"
android:orientation="vertical" >
<TextView
androi...
Jquery insert new row into table at a certain index
...$('#my_table > tbody:last').append(newRow); // this will add new row inside tbody
$("table#myTable tr").last().after(newRow); // this will add new row outside tbody
//i.e. between thead and tbody
//.befor...
Understanding the ngRepeat 'track by' expression
...
You can track by $index if your data source has duplicate identifiers
e.g.: $scope.dataSource: [{id:1,name:'one'}, {id:1,name:'one too'}, {id:2,name:'two'}]
You can't iterate this collection while using 'id' as identifier (duplicate id:1).
WON'T WORK:
<element ng-repeat="item...