大约有 13,916 项符合查询结果（耗时：0.0214秒） [XML]
How to drop a table if it exists?
...
Is it correct to do the following?
IF EXISTS(SELECT *
FROM dbo.Scores)
DROP TABLE dbo.Scores
No. That will drop the table only if it contains any rows (and will raise an error if the table does not exist).
Instead, for a permanent table you can ...
Regex doesn't work in String.matches()
...tely, other languages have followed suit :(
If you want to see if the regex matches an input text, use a Pattern, a Matcher and the .find() method of the matcher:
Pattern p = Pattern.compile("[a-z]");
Matcher m = p.matcher(inputstring);
if (m.find())
// match
If what you want is indeed to se...
In Mongoose, how do I sort by date? (node.js)
...leases such that some of these answers are no longer valid. As of the 4.1.x release of Mongoose, a descending sort on the date field can be done in any of the following ways:
Room.find({}).sort('-date').exec(function(err, docs) { ... });
Room.find({}).sort({date: -1}).exec(function(err, docs) { .....
Cross Domain Form POSTing
..., such as Printers and Routers.
There are many ways of building a CSRF exploit. A simple POST based CSRF attack can be sent using .submit() method. More complex attacks, such as cross-site file upload CSRF attacks will exploit CORS use of the xhr.withCredentals behavior.
CSRF does not violat...
Does the C++ standard mandate poor performance for iostreams, or am I just dealing with a poor imple
...on IOStreams (p.68). Most relevant to your question is in Section 6.1.2 ("Execution Speed"):
Since certain aspects of IOStreams processing are
distributed over multiple facets, it
appears that the Standard mandates an
inefficient implementation. But this
is not the case — by using some...
Displaying the #include hierarchy for a C++ file in Visual Studio
...+ project that I'm trying to migrate to Visual Studio 2010. It's a huge mix of stuff from various sources and of various ages. I'm getting problems because something is including both winsock.h and winsock2.h .
...
Can't install via pip because of egg_info error
...n in powershell or command prompt, navigate to ez_setup’s directory and execute the command and this will run the file for you:
$ [sudo] python ez_setup.py
If you still need to install pip at this point, run:
$ [sudo] easy_install pip
easy_install was part of the setuptools, and therefore w...
Postgresql - unable to drop database because of some auto connections to DB
...roles; see \l+ in psql)
You can then terminate all connections to this db except your own:
SELECT pid, pg_terminate_backend(pid)
FROM pg_stat_activity
WHERE datname = current_database() AND pid <> pg_backend_pid();
On older versions pid was called procpid so you'll have to deal with that.
S...
How to go back in Eclipse?
...n Eclipse? Basically, when I'm jumping around a big project following the execution flow (ctrl + click and etc.), is there a way to retrace a step? If my code calls a method and I go to the method definition, is there a key combination that will take me back to the calling code?
...
CSS center display inline block?
...rizontally and vertically centered within a 100% width parent.
I used Flexbox's justify-content and align-items properties, which respectively allow you to center elements horizontally and vertically. By setting both to center on the parent, the child element (or even multiple elements!) will be p...