大约有 40,000 项符合查询结果（耗时：0.0314秒） [XML]
Which is faster/best? SELECT * or SELECT column1, colum2, column3, etc
...nificant practical reason is that it forces the user to magically know the order in which columns will be returned. It's better to be explicit, which also protects you against the table changing, which segues nicely into...
If a column name you're using changes, it's better to catch it early (at the...
Asynchronous Process inside a javascript for loop [duplicate]
.../rejected when the asynchronous operation is complete. Also, note that in order to use await, the containing function must be declared async.
Run asynchronous operations in parallel and use Promise.all() to collect results in order
function someFunction() {
let promises = [];
for (let ...
How do I find duplicate values in a table in Oracle?
...= oed.deptid )
group by oed.empid having count(oed.empid) > 1 order by count(oed.empid);
and if such table has primary key then use primary key instead of rowid, e.g id is pk then
select oed.empid, count(oed.empid)
from emp_dept oed
where exists ( select *
from emp...
Detect when a window is resized using JavaScript ?
... ", window.innerWidth, "px");
}
window.onresize = resize;
<p>In order for this code snippet to work as intended, you will need to either shrink your browser window down to the size of this code snippet, or fullscreen this code snippet and resize from there.</p>
...
Can I get the name of the current controller in the view?
... If you have your controller behind a namespace like this: Admin::Orders then controller_name and params[:controller] will be "orders" and "admin/orders" respectively.
– Viktor Fonic
Sep 23 '13 at 8:10
...
What is q=0.5 in Accept* HTTP headers?
...
Very nice, thanks! But why not just list them in the order of preference?
– kolypto
Dec 18 '11 at 16:12
9
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Are static class instances unique to a request or a server in ASP.NET?
...ferent requests may or may not be handled by the same worker process.
In order to share data with a specific user and across requests, use HttpContext.Current.Session.
In order to share data within a specific request, use HttpContext.Current.Items.
In order to share data across the entire applicat...
Avoid synchronized(this) in Java?
...angerous. You've now introduced a client-side (user's of this class) lock ordering requirement. If two threads are calling method1() and method2() in a different order, they are likely to deadlock, but the user of this class has no idea that this is the case.
– daveb
...
“Comparison method violates its general contract!”
...ode:
public int compareTo(tfidfContainer compareTfidf) {
//descending order
if (this.tfidf > compareTfidf.tfidf)
return -1;
else if (this.tfidf < compareTfidf.tfidf)
return 1;
else
return 0;
}
The transitive property clearly holds, but for some re...
How do you make lettered lists using markdown?
Markdown allows ordered lists using numbers. How can I instead get an ordered list using letters ? i.e.
5 Answers
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