大约有 40,000 项符合查询结果（耗时：0.0643秒） [XML]
JPA EntityManager: Why use persist() over merge()?
...ed (any changes you make will not be part of the transaction - unless you call merge again). You can through use returned instance (managed one).
Maybe a code example will help.
MyEntity e = new MyEntity();
// scenario 1
// tran starts
em.persist(e);
e.setSomeField(someValue);
// tran ends, an...
Dynamic validation and name in a form with AngularJS
...d) and the suggested approach by the angular team (from docs.angularjs.org/api/ng.directive:form): "Since you cannot dynamically generate the name attribute of input elements using interpolation, you have to wrap each set of repeated inputs in an ngForm directive and nest these in an outer form elem...
Techniques for Tracing Constraints
... and GHC complains could not deduce x ~ y for some x and y . You can usually throw GHC a bone and simply add the isomorphism to the function constraints, but this is a bad idea for several reasons:
...
What is the leading LINQ for JavaScript library? [closed]
I'm looking for a JavaScript library that will allow me to query complex JSON objects using a LINQ-like syntax. A quick search found a couple of promising options that look they might offer what I need:
...
How to store arbitrary data for some HTML tags
...
Which version of HTML are you using?
In HTML 5, it is totally valid to have custom attributes prefixed with data-, e.g.
<div data-internalid="1337"></div>
In XHTML, this is not really valid. If you are in XHTML 1.1 mode, the browser will probably complain about it, b...
Ruby on Rails. How do I use the Active Record .build method in a :belongs to relationship?
...
Where it is documented:
From the API documentation under the has_many association in "Module ActiveRecord::Associations::ClassMethods"
collection.build(attributes = {}, …)
Returns one or more new objects of the
collection type that have been
inst...
Is there a builtin identity function in python?
...hink about the signature and time costs.
So a better way to do it is actually (a lambda avoids naming the function):
_ = lambda *args: args
advantage: takes any number of parameters
disadvantage: the result is a boxed version of the parameters
OR
_ = lambda x: x
advantage: doesn't change...
Passing an Array as Arguments, not an Array, in PHP
...dard func($arg1, $arg2) manner. But now I'm lost on how to do it. I recall the manner of passing by reference, how to "glob" incoming parameters ... but not how to de-list the array into a list of arguments.
...
if checkbox is checked, do this
...me power of jQuery to access properties of an element. The article specifically treats the use of .attr("id") but in the case that #checkbox is an <input type="checkbox" /> element the issue is the same for $(...).attr('checked') (or even $(...).is(':checked')) vs. this.checked.
...
In C#, What is a monad?
...
Most of what you do in programming all day is combining some functions together to build bigger functions from them. Usually you have not only functions in your toolbox but also other things like operators, variable assignments and the like, but generally your...