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How to check if a process id (PID) exists
...will have a race condition.
If you want to ignore the text output of kill and do something based on the exit code, you can
if ! kill $pid > /dev/null 2>&1; then
echo "Could not send SIGTERM to process $pid" >&2
fi
...
throwing exceptions out of a destructor
... fails... There is really no good way to protect against exceptions thrown from destructors, so the library makes no guarantees if an element destructor throws" (from Appendix E3.2) .
...
how to get program files x86 env variable?
... C:\Program Files (x86)
echo %ProgramW6432% ==> C:\Program Files
From Wikipedia:
The %ProgramFiles% variable points to the Program Files directory,
which stores all the installed programs of Windows and others. The
default on English-language systems is "C:\Program Files". In 64-bi...
LISTAGG in Oracle to return distinct values
...
19c and later:
select listagg(distinct the_column, ',') within group (order by the_column)
from the_table
18c and earlier:
select listagg(the_column, ',') within group (order by the_column)
from (
select distinct the_column
from t...
Best way to test if a row exists in a MySQL table
...
You could also try EXISTS:
SELECT EXISTS(SELECT * FROM table1 WHERE ...)
and per the documentation, you can SELECT anything.
Traditionally, an EXISTS subquery starts with SELECT *, but it could
begin with SELECT 5 or SELECT column1 or anything ...
Chrome browser reload options new feature
... you get this tooltip saying: "Reload this page, hold to see more options" and when I do it I get these three awesome options.
1. Normal Reload
2. Hard Reload
3. Empty Cache and Hard Reload (this is very useful option I believe)
...
Removing projects in Sublime Text 2 and 3
How do you remove a project from Sublime Text 2 and 3's project windows ( Ctrl + Alt + P ) ?
5 Answers
...
LinkedBlockingQueue vs ConcurrentLinkedQueue
...mes in, and inefficiencies when it's empty (due to waking up unnecessarily from sleeps).
From the docs for BlockingQueue:
BlockingQueue implementations are designed to be used primarily for producer-consumer queues
I know it doesn't strictly say that only blocking queues should be used for pr...
How can I select from list of values in SQL Server
... would be to use a find an replace with UNION to get the distinct values.
SELECT 1
UNION SELECT 1
UNION SELECT 1
UNION SELECT 2
UNION SELECT 5
UNION SELECT 1
UNION SELECT 6
Applied to your long line of comma delimited text
Find and replace every comma with UNION SELECT
Add a SELECT in front of ...
How to filter SQL results in a has-many-through relation
...
Results:
Total runtimes from EXPLAIN ANALYZE.
1) Martin 2: 44.594 ms
SELECT s.stud_id, s.name
FROM student s
JOIN student_club sc USING (stud_id)
WHERE sc.club_id IN (30, 50)
GROUP BY 1,2
HAVING COUNT(*) > 1;
2) Erwin 1: 33.217 ms
SELECT s.stud_id, s.name
FROM student s
JOIN ...