大约有 41,000 项符合查询结果（耗时：0.0332秒） [XML]
Which is fastest? SELECT SQL_CALC_FOUND_ROWS FROM `table`, or SELECT COUNT(*)
...irm this - I just updated a query with 4 joins on a 168,000 row database. Selecting just the first 100 rows with a SQL_CALC_FOUND_ROWS took over 20 seconds; using a separate COUNT(*) query took under 5 seconds (for both count + results queries).
– Sam Dufel
Ju...
How to select option in drop down using Capybara
I'm trying to select an item from a drop down menu using Capybara (2.1.0).
9 Answers
9...
How to grep a text file which contains some binary data?
...<test.log | grep whatever
This will change anything less than a space character (except newline) and anything greater than 126, into a . character, leaving only the printables.
If you want every "illegal" character replaced by a different one, you can use something like the following C progr...
How can I find the last element in a List?
...ndLast(_ => true);, but I find just the underscore (or any other single character identifier) can be a bit confusing at times.
– Bob
Jan 29 '13 at 5:56
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Set selected option of select box
I want to set a option that was selected previously to be displayed on page load. I tried it with the following code:
16 An...
Return a value if no rows are found in Microsoft tSQL
...
SELECT CASE WHEN COUNT(1) > 0 THEN 1 ELSE 0 END AS [Value]
FROM Sites S
WHERE S.Id = @SiteId and S.Status = 1 AND
(S.WebUserId = @WebUserId OR S.AllowUploads = 1)
...
How to filter SQL results in a has-many-through relation
...
Results:
Total runtimes from EXPLAIN ANALYZE.
1) Martin 2: 44.594 ms
SELECT s.stud_id, s.name
FROM student s
JOIN student_club sc USING (stud_id)
WHERE sc.club_id IN (30, 50)
GROUP BY 1,2
HAVING COUNT(*) > 1;
2) Erwin 1: 33.217 ms
SELECT s.stud_id, s.name
FROM student s
JOIN ...
Preventing an image from being draggable or selectable without using JS
Does anyone know of a way to make an image not draggable and not selectable -- at the same time -- in Firefox, without resorting to Javascript? Seems trivial, but here's the issue:
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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)
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Can you create nested WITH clauses for Common Table Expressions?
..., the form of the statement you are looking for would be
WITH x AS
(
SELECT * FROM MyTable
),
y AS
(
SELECT * FROM x
)
SELECT * FROM y
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