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Select first row in each GROUP BY group?
... SELECT p.id,
p.customer,
p.total,
ROW_NUMBER() OVER(PARTITION BY p.customer
ORDER BY p.total DESC) AS rk
FROM PURCHASES p)
SELECT s.*
FROM summary s
WHERE s.rk = 1
Supported by any database:
But you need to add logic...
Extract elements of list at odd positions
...ust a notation for list slicing. Usually it is in the following form:
some_list[start:stop:step]
If we omitted start, the default (0) would be used. So the first element (at position 0, because the indexes are 0-based) would be selected. In this case the second element will be selected.
Because ...
What does static_assert do, and what would you use it for?
Could you give an example where static_assert(...) ('C++11') would solve the problem in hand elegantly?
8 Answers
...
Understanding Apache's access log
... 369 74500 - 567 what do they indicate?
– my account_ram
Jan 29 '14 at 21:18
add a comment
...
How can I group data with an Angular filter?
...ddle.net/TD7t3/
The filter
app.filter('groupBy', function() {
return _.memoize(function(items, field) {
return _.groupBy(items, field);
}
);
});
Note the 'memoize' call. This underscore method caches the result of the function and stops angular from evaluating the fil...
Handling specific errors in JavaScript (think exceptions)
...
try-catch-finally.js
Using try-catch-finally.js, you can call the _try function with an anonymous callback, which it will call, and you can chain .catch calls to catch specific errors, and a .finally call to execute either way.
Example
_try(function () {
throw 'My error';
})
.catch(Erro...
How to scroll to specific item using jQuery?
...ple. No plugins needed.
var $container = $('div'),
$scrollTo = $('#row_8');
$container.scrollTop(
$scrollTo.offset().top - $container.offset().top + $container.scrollTop()
);
// Or you can animate the scrolling:
$container.animate({
scrollTop: $scrollTo.offset().top - $container.offse...
Concept of void pointer in C programming
...ligned at 4-byte boundary to be dereferenced).
For example, reading uint16_t from void*:
/* may receive wrong value if ptr is not 2-byte aligned */
uint16_t value = *(uint16_t*)ptr;
/* portable way of reading a little-endian value */
uint16_t value = *(uint8_t*)ptr
| ((*((uint8_t*)...
Can Selenium Webdriver open browser windows silently in background?
...river
from selenium.webdriver.chrome.options import Options
CHROME_PATH = '/usr/bin/google-chrome'
CHROMEDRIVER_PATH = '/usr/bin/chromedriver'
WINDOW_SIZE = "1920,1080"
chrome_options = Options()
chrome_options.add_argument("--headless")
chrome_options.add_argument(...
Get list of all routes defined in the Flask app
...
All the routes for an application are stored on app.url_map which is an instance of werkzeug.routing.Map. You can iterate over the Rule instances by using the iter_rules method:
from flask import Flask, url_for
app = Flask(__name__)
def has_no_empty_params(rule):
defaults...