大约有 46,000 项符合查询结果(耗时:0.0280秒) [XML]
Prevent text selection after double click
...lick event on a span in my web app. A side-effect is that the double click selects text on the page. How can I prevent this selection from happening?
...
Javascript/jQuery: Set Values (Selection) in a multiple Select
I have a multiple select:
8 Answers
8
...
What is the “N+1 selects problem” in ORM (Object-Relational Mapping)?
The "N+1 selects problem" is generally stated as a problem in Object-Relational mapping (ORM) discussions, and I understand that it has something to do with having to make a lot of database queries for something that seems simple in the object world.
...
How can I SELECT rows with MAX(Column value), DISTINCT by another column in SQL?
...
You are so close! All you need to do is select BOTH the home and its max date time, then join back to the topten table on BOTH fields:
SELECT tt.*
FROM topten tt
INNER JOIN
(SELECT home, MAX(datetime) AS MaxDateTime
FROM topten
GROUP BY home) groupedtt...
Why is SELECT * considered harmful?
Why is SELECT * bad practice? Wouldn't it mean less code to change if you added a new column you wanted?
15 Answers
...
How to get next/previous record in MySQL?
...
next:
select * from foo where id = (select min(id) from foo where id > 4)
previous:
select * from foo where id = (select max(id) from foo where id < 4)
...
Changing selection in a select with the Chosen plugin
I'm trying to change the currently selected option in a select with the Chosen plugin.
4 Answers
...
Is it possible to style a select box? [closed]
I've got an HTML select box that I need to style. I'd prefer to use just CSS but if I have to I'll use jQuery to fill in the gaps.
...
You can't specify target table for update in FROM clause
...llow you to write queries like this:
UPDATE myTable
SET myTable.A =
(
SELECT B
FROM myTable
INNER JOIN ...
)
That is, if you're doing an UPDATE/INSERT/DELETE on a table, you can't reference that table in an inner query (you can however reference a field from that outer table...)
Th...
quick random row selection in Postgres
...
You might want to experiment with OFFSET, as in
SELECT myid FROM mytable OFFSET floor(random()*N) LIMIT 1;
The N is the number of rows in mytable. You may need to first do a SELECT COUNT(*) to figure out the value of N.
Update (by Antony Hatchkins)
You must use floor he...