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MySQL - SELECT WHERE field IN (subquery) - Extremely slow why?
...NNER JOIN sometable st2 ON (st1.relevant_field = st2.relevant_field)
GROUP BY st1.id /* list a unique sometable field here*/
HAVING COUNT(*) > 1
I think st2.relevant_field must be in the select, because otherwise the having clause will give an error, but I'm not 100% sure
Never use IN with a ...
Average of 3 long integers
...aged semantics of the modulo operation, this can give a result that is off by one, namely rounded up rather than down, if negative values for the variables are allowed. For instance if x,y are positive multiples of 3, and z is -2, you get (x+y)/3 which is too much.
– Marc van L...
Selecting pandas column by location
I'm simply trying to access named pandas columns by an integer.
5 Answers
5
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What exactly does git's “rebase --preserve-merges” do (and why?)
...now what they are.
So first, figure out which parents to use for c', by reference to the parents of c:
For each parent p_i in parents_of(c):
If p_i is one of the merge bases mentioned above:
# p_i is one of the "boundary commits" that we no longer want to use as p...
Select parent element of known element in Selenium
...e straightforward.
JavaScript:
WebElement myElement = driver.findElement(By.id("myDiv"));
WebElement parent = (WebElement) ((JavascriptExecutor) driver).executeScript(
"return arguments[0].parentNode;", myElement);
XPath:
WebElement myElement = driver.findElem...
How to select the last record of a table in SQL?
...t we can do is something like
Sql Server
SELECT TOP 1 * FROM Table ORDER BY ID DESC
MySql
SELECT * FROM Table ORDER BY ID DESC LIMIT 1
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How to sort a list/tuple of lists/tuples by the element at a given index?
...
sorted_by_second = sorted(data, key=lambda tup: tup[1])
or:
data.sort(key=lambda tup: tup[1]) # sorts in place
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List all developers on a project in Git
...
(users that have done commits)
Note: by default git shortlog groups commits by authors.
If you need to group them by committers, you will need Git 2.12 (Q1 2017)
git shortlog -snc
See commit 03f4082 (16 Dec 2016) by Jeff King (peff).
See commit fbfda15 (11 O...
In what order are Panels the most efficient in terms of render time and performance?
...of these two passes.
The performance of the measure pass is most affected by the ability of a panel to accommodate stretching using alignments (or Auto in the case of the Grid) and then the number of children which are stretched or auto-sized. The performance of the Arrange pass is affected by the...
MySQL Data - Best way to implement paging?
...on:
The LIMIT clause can be used to constrain the number of rows returned by the SELECT statement. LIMIT takes one or two numeric arguments, which must both be nonnegative integer constants (except when using prepared statements).
With two arguments, the first argument specifies the offset of the f...