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How to insert a newline in front of a pattern?
...adability - the only caveat is that you then need to double all literal \ chars.
– mklement0
Nov 30 '15 at 3:59
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When to use ' (or quote) in Lisp?
...WITH-STRING (LENGTH STRING))
Hey! That's not what we wanted. We want to selectively evaluate some arguments, and leave the others as symbols. Try #2!
(defun mess-with (number string)
(list 'value-of-number (1+ number) 'something-with-string (length string)))
Lisp> (mess-with 20 "foo")
(VAL...
Row count with PDO
...
$sql = "SELECT count(*) FROM `table` WHERE foo = ?";
$result = $con->prepare($sql);
$result->execute([$bar]);
$number_of_rows = $result->fetchColumn();
Not the most elegant way to do it, plus it involves an extra query...
Using group by on multiple columns
..., to do with who is attending what subject at a university:
Table: Subject_Selection
+---------+----------+----------+
| Subject | Semester | Attendee |
+---------+----------+----------+
| ITB001 | 1 | John |
| ITB001 | 1 | Bob |
| ITB001 | 1 | Mickey |
| ITB001 ...
Select row with most recent date per user
...
Query:
SQLFIDDLEExample
SELECT t1.*
FROM lms_attendance t1
WHERE t1.time = (SELECT MAX(t2.time)
FROM lms_attendance t2
WHERE t2.user = t1.user)
Result:
| ID | USER | TIME | IO |
---------------------------...
How to change options of with jQuery?
Suppose a list of options is available, how do you update the <select> with new <option> s?
9 Answers
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What's faster, SELECT DISTINCT or GROUP BY in MySQL?
...'t, then use DISTINCT.
GROUP BY in MySQL sorts results. You can even do:
SELECT u.profession FROM users u GROUP BY u.profession DESC
and get your professions sorted in DESC order.
DISTINCT creates a temporary table and uses it for storing duplicates. GROUP BY does the same, but sortes the disti...
Algorithm to detect intersection of two rectangles?
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In Cocoa you could easily detect whether the selectedArea rect intersects your rotated NSView's frame rect.
You don't even need to calculate polygons, normals an such. Just add these methods to your NSView subclass.
For instance, the user selects an area on the NSView's...
React JSX: selecting “selected” on selected option
In a React component for a <select> menu, I need to set the selected attribute on the option that reflects the application state.
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How to prevent line break at hyphens on all browsers
...liably than splitting the text to “words” (sequences of non-whitespace characters separated by whitespace) and wrapping each “word” that contains a hyphen inside nobr markup. So input data like bla bla foo-bar bla bla would be turned to bla bla <nobr>foo-bar</nobr> bla bla.
You ...