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What does the * * CSS selector do?
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Just like any other time you put two selectors one after another (for example li a), you get the descendant combinator. So * * is any element that is a descendant of any other element — in other words, any element that isn't the root element of the whole docum...
Django ManyToMany filter()
...d it.
the above code will end up generating SQL that looks something like:
SELECT * FROM users WHERE id IN (SELECT user_id FROM userzones WHERE zone_id IN (1,2,3))
which is nice because it doesn't have any intermediate joins that could cause duplicate users to be returned
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Get the first item from an iterable that matches a condition
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Since this is the selected answer, I feel compelled to share an answer to selecting the first element correctly here. In short: usage of next shouldn't be encouraged.
– guyarad
Jul 7 '16 at 10:56
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Debugging iframes with Chrome developer tools
...ools in Chrome, there is a bar along the top, called the Execution Context Selector (h/t felipe-sabino), just under the Elements, Network, Sources... tabs, that changes depending on the context of the current tab. When in the Console tab there is a dropdown in that bar that allows you to select the...
How to join (merge) data frames (inner, outer, left, right)
...s these operations in SQL.
library(sqldf)
## inner join
df3 <- sqldf("SELECT CustomerId, Product, State
FROM df1
JOIN df2 USING(CustomerID)")
## left join (substitute 'right' for right join)
df4 <- sqldf("SELECT CustomerId, Product, State
FROM df1...
Checkout one file from Subversion
...ithin the repository containing all the files that you wish to work on and Select Checkout.
Step 3: Within new popup window, ensure that the checkout directory points to the correct location on your local PC. There will also be a dropdown menu labeled “checkout depth”. Choose “Only this item...
Is there a way to make a link clickable in the OSX Terminal?
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I had always been selecting the URL first (dragging the cursor from the start to end of the URL), then right clicking. I learned today, while reading through these answers, that it was not necessary to select the URL; simply right clicking on ...
What is The difference between ListBox and ListView
...ew, but you can easily create your own.
Another difference is the default selection mode: it's Single for a ListBox, but Extended for a ListView
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Django in / not in query
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table1.objects.extra(where=["table1.id NOT IN (SELECT table2.key_to_table1 FROM table2 WHERE table2.id = some_parm)"])
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Combining CSS Pseudo-elements, “:after” the “:last-child”
...this reason: the last-child is a modifier on the li, and then after you've selected all li elements that are last children you then select (and implicitly create) a new element before and after each.
– Martin Atkins
Nov 15 '11 at 14:52
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