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Yes/No message box using QMessageBox
...lude <QApplication>
#include <QMessageBox>
int main(int argc, char **argv)
{
QApplication app{argc, argv};
while (QMessageBox::question(nullptr,
qApp->translate("my_app", "Test"),
qApp->translate("my_app", "...
Changing the selected option of an HTML Select element
In my HTML, I have a <select> with three <option> elements. I want to use jQuery to check each option's value against a Javascript var . If one matches, I want to set the selected attribute of that option. How would I do that?
...
How to do a FULL OUTER JOIN in MySQL?
...MPLE transcribed from this SO question you have:
with two tables t1, t2:
SELECT * FROM t1
LEFT JOIN t2 ON t1.id = t2.id
UNION
SELECT * FROM t1
RIGHT JOIN t2 ON t1.id = t2.id
The query above works for special cases where a FULL OUTER JOIN operation would not produce any duplicate rows. The quer...
How to select a single field for all documents in a MongoDB collection?
...nt such as:
db.student.find({}, {roll:1, _id:0})
The above statement will select all documents in the students collection, and the returned document will return only the roll field (and exclude the _id).
If we don't mention _id:0 the fields returned will be roll and _id. The '_id' field is always d...
SQL join: selecting the last records in a one-to-many relationship
... want to get a list of all customers along with their last purchase in one SELECT statement. What is the best practice? Any advice on building indexes?
...
Set select option 'selected', by value
I have a select field with some options in it. Now I need to select one of those options with jQuery. But how can I do that when I only know the value of the option that must be selected?
...
Check whether an input string contains a number in javascript
...pattern" is the regular expression itself, and "modifiers" are a series of characters indicating various options.
The character class is the most basic regex concept after a literal match. It makes one small sequence of characters match a larger set of characters. For example, [A-...
What is the bit size of long on 64-bit Windows?
...bit' and 'long, pointers are 64-bit'.
Type ILP64 LP64 LLP64
char 8 8 8
short 16 16 16
int 64 32 32
long 64 64 32
long long 64 64 64
pointer 64 64 64
The ILP64 sys...
Retrieving the last record in each group - MySQL
...x, we can write greatest-n-per-group queries:
WITH ranked_messages AS (
SELECT m.*, ROW_NUMBER() OVER (PARTITION BY name ORDER BY id DESC) AS rn
FROM messages AS m
)
SELECT * FROM ranked_messages WHERE rn = 1;
Below is the original answer I wrote for this question in 2009:
I write the solu...
ruby on rails f.select options with custom attributes
I have a form select statement, like this:
5 Answers
5
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