大约有 40,000 项符合查询结果（耗时：0.0571秒） [XML]
How to add 'ON DELETE CASCADE' in ALTER TABLE statement
...t instead of modify constraint.
Now this is the command:
ALTER TABLE child_table_name
ADD CONSTRAINT fk_name
FOREIGN KEY (child_column_name)
REFERENCES parent_table_name(parent_column_name)
ON DELETE CASCADE;
s...
How to create a self-signed certificate for a domain name for development?
...ive you a hard time when they stubbornly refuse to match your domain motör_head.dev.local to your wildcard pattern *.dev.local. They will comply when you switch to motoer-head.dev.local.
A wildcard in a certificate will only match ONE label (= section between two dots) in a domain, never more. *.de...
How to log something in Rails in an independent log file?
...t like the usual Rails logger:
class User < ActiveRecord::Base
def my_logger
@@my_logger ||= Logger.new("#{Rails.root}/log/my.log")
end
def before_save
my_logger.info("Creating user with name #{self.name}")
end
end
Here I used a class attribute to memoize the logger. This way ...
Optional Parameters in Go?
...amp;Foobar{}
// ... (write initializations with default values)...
for _, op := range options{
err := op(fb)
if err != nil {
return nil, err
}
}
return fb, nil
}
where each option is a function which mutates the Foobar. Then provide convenient ways for your user to use or...
How do I set up IntelliJ IDEA for Android applications?
...n a Mac, the Java JDK appears at /Library/Java/JavaVirtualMachines/jdk1.7.0_09.jdk
– emrys57
Nov 22 '12 at 14:13
1
...
Is a URL allowed to contain a space?
...s separated by a white space. If you put a space in your url:
GET /url end_url HTTP/1.1
You know have 4 fields, the HTTP server will tell you it is an invalid request.
GET /url%20end_url HTTP/1.1
3 fields => valid
Note: in the query string (after ?), a space is usually encoded as a +
GET ...
ADB not recognising Nexus 4 under Windows 7
...B driver via SDK Manager.exe. In order to get that to run I had to set JAVA_HOME to the location of my JDK.
– Ben Challenor
Feb 9 '13 at 12:14
3
...
Understanding PrimeFaces process/update and JSF f:ajax execute/render attributes
...d="foo" value="#{bean.foo}" required="true" />
<p:message id="foo_m" for="foo" />
<p:inputText id="bar" value="#{bean.bar}" required="true" />
<p:message id="bar_m" for="bar" />
<p:commandButton action="#{bean.action}" update="@form" />
</h:form>
(no...
JsonMappingException: No suitable constructor found for type [simple type, class ]: can not instanti
...roperly. See exlanation here: cowtowncoder.com/blog/archives/2010/08/entry_411.html
– jpennell
Feb 14 '13 at 1:35
...
In Rails, how do you render JSON using a view?
...
You should be able to do something like this in your respond_to block:
respond_to do |format|
format.json
render :partial => "users/show.json"
end
which will render the template in app/views/users/_show.json.erb.
...