大约有 40,000 项符合查询结果（耗时：0.0584秒） [XML]
Which SQL query is faster? Filter on Join criteria or Where clause?
...
Performance-wise, they are the same (and produce the same plans)
Logically, you should make the operation that still has sense if you replace INNER JOIN with a LEFT JOIN.
In your very case this will look like this:
SELECT *
FROM TableA a
LEFT JOIN
TableXRef x
ON x.TableAID = ...
How to send a PUT/DELETE request in jQuery?
...ch as PUT and DELETE, can also be used here, but they are not supported by all browsers." from: api.jquery.com/jQuery.ajax/#options
– andilabs
Dec 2 '13 at 8:11
23
...
How do I format a string using a dictionary in python-3.x?
...3). In many languages, it is known as splat operator. In JavaScript, it's called spread operator. In python, there is no particular name given to this operator.
– abhisekp
Apr 15 '17 at 12:01
...
Storing time-series data, relational or non?
... description, the actual PK is (Device, Metric, DateTime). (Please don't call it TimeStamp, that means something else, but that is a minor issue.) The uniqueness of the row is identified by:
(Device, Metric, DateTime)
The Id column does nothing, it is totally and completely redundant.
A...
Check if two unordered lists are equal [duplicate]
...has a built-in datatype for an unordered collection of (hashable) things, called a set. If you convert both lists to sets, the comparison will be unordered.
set(x) == set(y)
Documentation on set
EDIT: @mdwhatcott points out that you want to check for duplicates. set ignores these, so you need ...
Navigation in django
...
I like this idea a lot, especially for flexibility, but it comes with the less-DRY trade-off. I did start using this in a site though.
– anonymous coward
Sep 22 '09 at 14:47
...
ElasticSearch - Return Unique Values
...h with high-cardinality datasets, but it's generally pretty accurate in my testing.
You can also tune the accuracy with the precision_threshold parameter. The trade-off, or course, is memory usage.
This graph from the docs shows how a higher precision_threshold leads to much more accurate results....
Looping through localStorage in HTML5 and JavaScript
...
In addition to all the other answers, you can use $.each function from the jQuery library:
$.each(localStorage, function(key, value){
// key magic
// value magic
});
Eventually, get the object with:
JSON.parse(localStorage.getI...
Multi-Line Comments in Ruby?
.....is kinda ugly and creates
a String instance, but I know one guy
with a Smalltalk background, who
does this."
puts "Hello world!"
##
# most
# people
# do
# this
__END__
But all forgot there is another option.
Only at the end of a file, of course.
This is how it looks (via screenshot) - othe...
What is lexical scope?
...
I understand them through examples. :)
First, lexical scope (also called static scope), in C-like syntax:
void fun()
{
int x = 5;
void fun2()
{
printf("%d", x);
}
}
Every inner level can access its outer levels.
There is another way, called dynamic scope used by ...