大约有 40,000 项符合查询结果（耗时：0.0635秒） [XML]
Can someone explain collection_select to me in clear, simple terms?
...order(..) or something like that.
# In your example it is:
Author.all,
# then you should specify methods for generating options
:id, # this is name of method that will be called for every row, result will be set as key
:name_with_initial, # this is name of method that will be ...
How to use '-prune' option of 'find' in sh?
... test (up to and including -prune) will return false for the stuff you actually want (ie: the stuff you don't want to prune out).
Here's an example:
find . -name .snapshot -prune -o -name '*.foo' -print
This will find the "*.foo" files that aren't under ".snapshot" directories. In this example, -na...
How to move a file?
...
os.rename(), shutil.move(), or os.replace()
All employ the same syntax:
import os
import shutil
os.rename("path/to/current/file.foo", "path/to/new/destination/for/file.foo")
shutil.move("path/to/current/file.foo", "path/to/new/destination/for/file.foo")
os.replace("p...
Group query results by month and year in postgresql
...he "date" attribute.
sum("Sales") as "Sales" : The SUM() function adds up all the "Sales" values, and supplies a case-sensitive alias, with the case sensitivity maintained by using double-quotes.
group by 1,2 : The GROUP BY function must contain all columns from the SELECT list that are not part o...
public friend swap member function
...truct vector
{
void swap(vector&) { /* swap members */ }
};
Naturally, then, our class should too, right? Well, not really. The standard library has all sorts of unnecessary things, and a member swap is one of them. Why? Let's go on.
What we should do is identify what's canonical, and w...
git revert back to certain commit [duplicate]
how do i revert all my files on my local copy back to a certain commit?
3 Answers
3
...
JQuery - $ is not defined
...ge is fully loaded, and as such, before jQuery is fully loaded.
First of all, ensure, what script is call properly, it should looks like
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js" type="text/javascript"></script>
and shouldn't have attributes async...
Why both no-cache and no-store should be used in HTTP response?
...ce is still valid then the cache can respond with its representation, thus alleviating the need for the server to resend the entire resource.
no-store is effectively the full do not cache directive and is intended to prevent storage of the representation in any form of cache whatsoever.
I say what...
Postgres: INSERT if does not exist already
... if one modifies the table such that more columns are unique. In that case all the scripts must be modified. It would be nice if there was a more generic way to do this...
– Willem Van Onsem
Aug 1 '14 at 13:17
...
How to make input type= file Should accept only pdf and xls
...
You could do so by using the attribute accept and adding allowed mime-types to it. But not all browsers do respect that attribute and it could easily be removed via some code inspector. So in either case you need to check the file type on the server side (your second question).
Ex...