大约有 19,000 项符合查询结果（耗时：0.0378秒） [XML]
How to change a nullable column to not nullable in a Rails migration?
...
This worked for me. Using MySql locally. When pushed and ran app in Heroku (Postgres) it crapped on column that was not null when I was writing it a null - rightfully so. Only "change_column_null" would work could not use "change_column ... :null =>...
MongoDb query condition on comparing 2 fields
...t those with condition Grade1 > Grade2 , how can I get a query like in MySQL?
4 Answers
...
PowerShell script to return versions of .NET Framework on a machine?
...he full version for the 4.x Framework. The earlier answers both return the root number on my system for .NET 3.0 (where the WCF and WPF numbers, which are nested under 3.0, are higher -- I can't explain that), and fail to return anything for 4.0 ...
EDIT: For .Net 4.5 and up, this changed slightly...
服务器保持大量TIME_WAIT和CLOSE_WAIT的解决方法 - C/C++ - 清泛网 - 专注C/C++及内核技术
...eb服务器也是会出现大量的TIME_WAIT的情况的。
现在来说如何来解决这个问题，解决思路很简单，就是让服务器能够快速回收和重用那些TIME_WAIT的资源。
下面来看一下我们网管对/etc/sysctl.conf文件的修改：
#对于一个新建连...
Create subdomains on the fly with .htaccess (PHP)
...ecessary :)
function create_subdomain($subDomain,$cPanelUser,$cPanelPass,$rootDomain) {
// $buildRequest = "/frontend/x3/subdomain/doadddomain.html?rootdomain=" . $rootDomain . "&domain=" . $subDomain;
$buildRequest = "/frontend/x3/subdomain/doadddomain.html?rootdomain=" . $rootDomai...
How do I make a Git commit in the past?
... your new commit. If you actually want your new file to be added via a new root commit (no parents), then you need something a bit different:
B---C---o---o---o master
git checkout master
git checkout --orphan new-root
git rm -rf .
git add path/to/file
GIT_AUTHOR_DATE='whenever' git commit
git ch...
Does a foreign key automatically create an index?
... I'm just about positive that PostgreSQL creates an index. I'm pretty sure MySQL does. Making the index makes a ton of sense, but IT'T NOT REQUIRED. After all, why reference something if every time the DB goes to look it up it has to do a tablescan?
– MBCook
Ma...
How can I access and process nested objects, arrays or JSON?
...st be a leaf node
return node;
}
}
const first_leaf = getLeaf(root);
const root = {
leftChild: {
leftChild: {
leftChild: null,
rightChild: null,
data: 42
},
rightChild: {
leftChild: null,
...
.war vs .ear file
...ch as application security role mapping, EJB reference mapping and context root URL mapping of web modules.
Apart from Web modules and EJB modules, EAR files can also contain connector modules packaged as RAR files and Client modules packaged as JAR files.
...
Difference between applicationContext.xml and spring-servlet.xml in Spring Framework
...nt-child hierarchy.
The applicationContext.xml defines the beans for the "root webapp context", i.e. the context associated with the webapp.
The spring-servlet.xml (or whatever else you call it) defines the beans for one servlet's app context. There can be many of these in a webapp, one per Sprin...