大约有 40,000 项符合查询结果（耗时：0.0279秒） [XML]
What's an Aggregate Root?
...re actually needed (as with lazy loading).
For example, you might have an Order object which encapsulates operations on multiple LineItem objects. Your client code would never load the LineItem objects directly, just the Order that contains them, which would be the aggregate root for that part of y...
What is an initialization block?
...ization blocks.
This code should illustrate the use of them and in which order they are executed:
public class Test {
static int staticVariable;
int nonStaticVariable;
// Static initialization block:
// Runs once (when the class is initialized)
static {
Syste...
Why doesn't java.lang.Number implement Comparable? [duplicate]
...m 2001:
All "numbers" are not comparable;
comparable assumes a total ordering of
numbers is possible. This is not even
true of floating-point numbers; NaN
(not a number) is neither less than,
greater than, nor equal to any
floating-point value, even itself.
{Float, Double}.compar...
How to get the parents of a Python class?
...
Usefully, this gives you all ancestor classes in the "method resolution order" -- i.e. the order in which the ancestors will be checked when resolving a method (or, actually, any other attribute -- methods and other attributes live in the same namespace in Python, after all;-).
...
What is the difference between bottom-up and top-down?
...nces: {Web: 1,2} {Literature: 5}
Recap
Dynamic programming is all about ordering your computations in a way that avoids recalculating duplicate work. You have a main problem (the root of your tree of subproblems), and subproblems (subtrees). The subproblems typically repeat and overlap.
For exam...
Concatenate multiple result rows of one column into one, group by another column [duplicate]
...cter, "char"), and some other types.
As isapir commented, you can add an ORDER BY clause in the aggregate call to get a sorted list - should you need that. Like:
SELECT movie, string_agg(actor, ', ' ORDER BY actor) AS actor_list
FROM tbl
GROUP BY 1;
But it's typically faster to sort rows in a...
Object.getOwnPropertyNames vs Object.keys
... least with nodejs) "getOwnPropertyNames" function does not guarantee keys order, that's why I usually use "keys" function :
Object.keys(o).forEach(function(k) {
if (!o.propertyIsEnumerable(k)) return;
// do something...
});
...
Does a foreign key automatically create an index?
...
Say you have a big table called orders, and a small table called customers. There is a foreign key from an order to a customer. Now if you delete a customer, Sql Server must check that there are no orphan orders; if there are, it raises an error.
To check ...
How to Remove Array Element and Then Re-Index Array?
... even if the keys will be reassigned, in the correct answer, the initial order will be kept.
– s3v3n
Apr 29 '11 at 6:35
1
...
Iterating over all the keys of a map
...
As a possible gotcha, note that the order of the iteration is undefined. groups.google.com/d/msg/golang-nuts/YfDxpkI34hY/4pktJI2ytusJ
– mna
Sep 22 '12 at 2:18
...