大约有 40,000 项符合查询结果（耗时：0.0411秒） [XML]
Using IQueryable with Linq
...t;T>. Say, for example, you have a Products table, and you want to get all of the products whose cost is >$25.
If you do:
IEnumerable<Product> products = myORM.GetProducts();
var productsOver25 = products.Where(p => p.Cost >= 25.00);
What happens here, is the database loads ...
Adding :default => true to boolean in existing Rails column
...
change_column is a method of ActiveRecord::Migration, so you can't call it like that in the console.
If you want to add a default value for this column, create a new migration:
rails g migration add_default_value_to_show_attribute
Then in the migration created:
# That's the more generic way t...
Create a tag in a GitHub repository
...m the official Linux Kernel Git documentation for git push:
--tags
All refs under refs/tags are pushed, in addition to refspecs explicitly listed on the command line.
Or if you just want to push a single tag:
git push origin <tag>
See also my answer to How do you push a tag to a r...
What are transparent comparators?
..., not by default.
The new member function template overloads of find etc. allow you to use a type that is comparable with the container's key, instead of using the key type itself. See N3465 by Joaquín Mª López Muñoz for rationale and a detailed, carefully written proposal to add this feature....
Hook up Raspberry Pi via Ethernet to laptop without router? [closed]
I'm working on a balloon project with a Raspberry Pi. When we potentially recover the Raspberry Pi, it will most likely be in a rural location and I'd like to turn off the Pi at that point safely.
...
Given a DateTime object, how do I get an ISO 8601 date in string format?
...xt in a format that is only correct for local times. This can happen when calling DateTime.ToString using the 'z' format specifier, which will include a local time zone offset in the output."
– Tom Lianza
Nov 2 '10 at 4:59
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Is it possible to use “/” in a filename?
...hould ever be done, but is there a way to use the slash character that normally separates directories within a filename in Linux?
...
Start ssh-agent on login
...a remote Git repo pulling from Bitbucket.com using an SSH alias. I can manually start the ssh-agent on my server but I have to do this every time I login via SSH.
...
What does void mean in C, C++, and C#?
... to be run and a pointer to the data to be passed to the function:
struct _deferred_work {
sruct list_head mylist;
.worker_func = bar;
.data = somedata;
} deferred_work;
Then a kernel thread goes over a list of deferred work and when it get's to this node it effectively executes:
bar(some...
Sleeping in a batch file
... a Windows box, I've needed to pause its execution for several seconds (usually in a test/wait loop, waiting for a process to start). At the time, the best solution I could find uses ping (I kid you not) to achieve the desired effect. I've found a better write-up of it here , which describes a call...