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Why does X[Y] join of data.tables not allow a full outer join, or a left join?
...Y) does both ways at the same time. The number of rows of X[Y] and Y[X] usually differ, whereas the number of rows returned by merge(X,Y) and merge(Y,X) is the same.
BUT that misses the main point. Most tasks require something to be done on the
data after a join or merge. Why merge all the co...
MySQL remove all whitespaces from the entire column
Is there a way to remove all whitespaces from a specific column for all values?
5 Answers
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Psql list all tables
I would like to list all tables in the liferay database in my PostgreSQL install. How do I do that?
6 Answers
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Are there console commands to look at whats in the queue and to clear the queue in Sidekiq?
... that there are methods just for viewing the queued jobs, but they would really just be wrappers around Redis commands, since that's basically all Sidekiq (and Resque) is:
# See workers
Sidekiq::Client.registered_workers
# See queues
Sidekiq::Client.registered_queues
# See all jobs for one queue
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Callback after all asynchronous forEach callbacks are completed
...veral ways to accomplish what you want:
Using a simple counter
function callback () { console.log('all done'); }
var itemsProcessed = 0;
[1, 2, 3].forEach((item, index, array) => {
asyncFunction(item, () => {
itemsProcessed++;
if(itemsProcessed === array.length) {
callback(...
Remove outline from select box in FF
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I found a solution, but it is mother of all hacks, hopefully it will serve as a starting point for other more robust solutions. The downside (too big in my opinion) is that any browser that doesn't support text-shadow but supports rgba (IE 9) won't render the text ...
What is the difference between NULL, '\0' and 0?
...0 has different meanings depending upon the context in which it's used. In all cases, it is still an integer constant with the value 0, it is just described in different ways.
If a pointer is being compared to the constant literal 0, then this is a check to see if the pointer is a null pointer. Thi...
Breakpoints are crossed out, how can I make them valid?
...a menu entry you have discovered for yourself that toggles the skipping of all breakpoints. There is also an icon for this in the "Breakpoints" View, and there may be a hot-key defined as well, all of which you may have triggered by accident.
Take a look at the Run -> Skip All Breakpoints.
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Redis command to get all available keys?
Is there a Redis command for fetching all keys in the database? I have seen some python-redis libraries fetching them. But was wondering if it is possible from redis-client.
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navbar color in Twitter Bootstrap
...or of the navbar of the Twitter Bootstrap 2.0.2? How can I change color of all the elements of the navbar to reflect the background color?
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