大约有 48,000 项符合查询结果（耗时：0.0410秒） [XML]
How accurately should I store latitude and longitude?
...
Actually, equator is best case. One latitude and one longitude degree are the same size at the equator (69 miles), but one degree of longitude shrinks to zero as it approaches either of the poles. Here's a very nice explanation: nationalatlas.gov/articles/mapping/a_latl...
What are the pros and cons of performing calculations in sql vs. in your application
...ed to access/aggregate a lot of data, doing it at the db server will save bandwidth, and disk io if the aggregates can be done inside indexes)
convenience (sql is not the best language for complex work - especially not great for procedural work, but very good for set-based work; lousy error-handling...
INSERT IF NOT EXISTS ELSE UPDATE?
... the ID column: In the replacement case the statement would set it to NULL and then a fresh ID would be allocated.
This approach can also be used if you want to leave particular field values alone if the row in the replacement case but set the field to NULL in the insert case.
For example, assumin...
Resolve absolute path from relative path and/or file name
...batch script to return an absolute path from a value containing a filename and/or relative path?
14 Answers
...
How to write inline if statement for print?
...n Python 2.5)
expression_if_true if condition else expression_if_false
And note, that both print a and b = a are statements. Only the a part is an expression. So if you write
print a if b else 0
it means
print (a if b else 0)
and similarly when you write
x = a if b else 0
it means
x = ...
How can I determine whether a 2D Point is within a Polygon?
..., but macOS for example uses float for everything. macOS only knows points and a point can translate to one pixel, but depending on monitor resolution, it might translate to something else. On retina screens half a point (0.5/0.5) is pixel. Still, I never noticed that macOS UIs are significantly slo...
WatiN or Selenium? [closed]
... tests of our presentation soon. It seems that everyone recommends WatiN and Selenium . Which do you prefer for automated testing of ASP.NET web forms? Which of these products work better for you?
...
Purge or recreate a Ruby on Rails database
...ave a dev Ruby on Rails database full of data. I want to delete everything and rebuild the database. I'm thinking of using something like:
...
Regex for splitting a string using space when not surrounded by single or double quotes
I'm new to regular expressions and would appreciate your help. I'm trying to put together an expression that will split the example string using all spaces that are not surrounded by single or double quotes. My last attempt looks like this: (?!") and isn't quite working. It's splitting on the spa...
Are loops really faster in reverse?
...
is it worth to introduce a variable for array.length and use it in the for loop's head?
– ragatskynet
Oct 30 '12 at 10:13
39
...