大约有 18,500 项符合查询结果（耗时：0.0300秒） [XML]
delete_all vs destroy_all?
...ach to delete records from a table. For instance, I have a user whose user ID is across many tables. I want to delete this user and every record that has his ID in all tables.
...
Table header to stay fixed at the top when user scrolls it out of view with jQuery
...ixed position to show the header at the top of the page.
HTML:
<table id="header-fixed"></table>
CSS:
#header-fixed {
position: fixed;
top: 0px; display:none;
background-color:white;
}
JavaScript:
var tableOffset = $("#table-1").offset().top;
var $header = $("#table-1...
How do I create a custom iOS view class and instantiate multiple copies of it (in IB)?
...t you can construct your interface in IB using a .xib file which is nearly identical to using the storyboard version; You should even be able to copy & paste your views as a whole from your existing interface to the .xib file.
To test this out I created a new empty .xib named "MyCustomTimerView...
How to create a drop shadow only on one side of an element?
...udo element is required.
#box {
background-color: #3D6AA2;
width: 160px;
height: 90px;
position: absolute;
top: calc(10% - 10px);
left: calc(50% - 80px);
}
.box-shadow:after {
content:"";
position:absolute;
width:100%;
bottom:1px;
z-ind...
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
...
What is the difference between JOIN and JOIN FETCH when using JPA and Hibernate
...
I use native query with Lazy fetch in both sides of relationship but still loads hierarchy of child relations.
– Badamchi
Dec 25 '19 at 12:18
...
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
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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...
【精心整理】【实用】visual C++中最常用的类与API函数 - C/C++ - 清泛网 -...
...个CArchive对象
CArchive(CFile* pFile,UINT nMode,int nBufSize=4096,void* lpBuf=NULL);
参数：pFile 指向CFile对象的指针，这个CFile对象是数据的最终源或目的；
nMode是标志，取值为CArchive::load时，从文档中加载数据（要求CFile读许可），取值为CArch...
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...