大约有 41,000 项符合查询结果（耗时：0.0500秒） [XML]
Return a `struct` from a function in C
... Yes, I can put an array inside a struct, but I cannot e.g. write typedef char arr[100]; arr foo() { ... } An array cannot be returned, even if the size is known.
– Giorgio
Mar 11 '12 at 11:19
...
Regular expression to limit number of characters to 10
...a regular expression that will only allow lowercase letters and up to 10 characters. What I have so far looks like this:
...
Generate GUID in MySQL for existing Data?
...e BEFORE UPDATE on YourTable
FOR EACH ROW
BEGIN
SET new.guid_column := (SELECT UUID());
END
//
Then execute
UPDATE YourTable set guid_column = (SELECT UUID());
And DROP TRIGGER beforeYourTableUpdate;
UPDATE
Another solution that doesn't use triggers, but requires primary key or unique inde...
how do I query sql for a latest record date for each user
...
select t.username, t.date, t.value
from MyTable t
inner join (
select username, max(date) as MaxDate
from MyTable
group by username
) tm on t.username = tm.username and t.date = tm.MaxDate
...
LEFT JOIN only first row
...rtist_id) will be the earliest.
So try something like this (untested...)
SELECT *
FROM feeds f
LEFT JOIN artists a ON a.artist_id = (
SELECT
MIN(fa.artist_id) a_id
FROM feeds_artists fa
WHERE fa.feed_id = f.feed_id
) a
...
Multiple line code example in Javadoc comment
...se of Eclipse, this is because of (bugged?) javadoc utility. If you have @ character in the multiline code inside {@code ...multiline...} then javadoc fails to parse it correctly:( At least this is what I see with Oracle JDK1.7.0_45 javadoc implementation.
– Male
...
How to get current time and date in C++?
...rentDateTime() {
time_t now = time(0);
struct tm tstruct;
char buf[80];
tstruct = *localtime(&now);
// Visit http://en.cppreference.com/w/cpp/chrono/c/strftime
// for more information about date/time format
strftime(buf, sizeof(buf), "%Y-%m-%d.%X", &tst...
Is there a __CLASS__ macro in C++?
...
That's better. As for knowing the class, defining char array sounds better than postponing it till runtime.
– Michael Krelin - hacker
Nov 3 '09 at 12:21
5
...
Does a break statement break from a switch/select?
I know that switch / select statements break automatically after every case. I am wondering, in the following code:
6 Ans...
Effect of NOLOCK hint in SELECT statements
...
1) Yes, a select with NOLOCK will complete faster than a normal select.
2) Yes, a select with NOLOCK will allow other queries against the effected table to complete faster than a normal select.
Why would this be?
NOLOCK typically (...