大约有 44,600 项符合查询结果（耗时：0.0461秒） [XML]
How to UPSERT (MERGE, INSERT … ON DUPLICATE UPDATE) in PostgreSQL?
...t's an EXAMPLE.
BEGIN;
UPDATE testtable
SET somedata = 'blah'
WHERE id = 2;
-- Remember, this is WRONG. Do NOT COPY IT.
INSERT INTO testtable (id, somedata)
SELECT 2, 'blah'
WHERE NOT EXISTS (SELECT 1 FROM testtable WHERE testtable.id = 2);
COMMIT;
then when two run at once there are several f...
How to avoid warning when introducing NAs by coercion
...
142
Use suppressWarnings():
suppressWarnings(as.numeric(c("1", "2", "X")))
[1] 1 2 NA
This supp...
How to take the first N items from a generator or list in Python? [duplicate]
...
526
Slicing a list
top5 = array[:5]
To slice a list, there's a simple syntax: array[start:stop:...
Laravel migration: unique key is too long, even if specified
...
1
2
Next
282
...
How to initialize an array's length in JavaScript?
... |
edited Jul 7 '15 at 15:21
answered Jan 31 '11 at 14:32
F...
How to smooth a curve in the right way?
...
275
I prefer a Savitzky-Golay filter. It uses least squares to regress a small window of your data...
SQlite Getting nearest locations (with latitude and longitude)
...method calculateDerivedPosition(...) calculates those points for you (p1, p2, p3, p4 in picture).
/**
* Calculates the end-point from a given source at a given range (meters)
* and bearing (degrees). This methods uses simple geometry equations to
* calculate the end-point.
*
* @param point
* ...
how to get the one entry from hashmap without iterating
...
answered Oct 2 '09 at 13:23
Per ÖstlundPer Östlund
1,15477 silver badges66 bronze badges
...
Extract a number from a string (JavaScript)
I have a string in JavaScript like #box2 and I just want the 2 from it.
21 Answers
...
How to mark a build unstable in Jenkins when running shell scripts
...
|
edited Oct 29 '13 at 9:22
answered Nov 16 '11 at 8:10
...