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SQL “select where not in subquery” returns no results
... FROM table1 t1
)
When table1.common_id is not nullable, all these queries are semantically the same.
When it is nullable, NOT IN is different, since IN (and, therefore, NOT IN) return NULL when a value does not match anything in a list containing a NULL.
This may be confusing bu...
What is a “static” function in C?
...n. For (C++/Java/...) class methods, static means that this method can be called on the class itself, no instance of that class necessary.
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follo...
Find value in an array
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array.select{} will go through all elements in the array looking those which match the condition. array.find instead will return the first element that match the condition. So preferable use array.find{ |e| e == 3 } then array.select{ |e| e == 3 }.first
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Does Firefox support position: relative on table elements?
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<div style="position:relative">
This will be positioned normally
<div style="position:absolute; top:5px; left:5px;">
This will be positioned at 5,5 relative to the cell
</div>
</div>
</td>
...
How do you push just a single Git branch (and no other branches)?
...
By default git push updates all the remote branches. But you can configure git to update only the current branch to it's upstream.
git config push.default upstream
It means git will update only the current (checked out) branch when you do git push.
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What's the meaning of 'origin' in 'git push origin master'
... an origin? stackoverflow.com/a/8248542/719689
– AlxVallejo
Aug 21 '12 at 13:06
5
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'IF' in 'SELECT' statement - choose output value based on column values
...tp://dev.mysql.com/doc/refman/5.0/en/control-flow-functions.html.
Additionally, you could handle when the condition is null. In the case of a null amount:
SELECT id,
IF(type = 'P', IFNULL(amount,0), IFNULL(amount,0) * -1) as amount
FROM report
The part IFNULL(amount,0) means when amount ...
Set “this” variable easily?
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There are two methods defined for all functions in JavaScript, call(), and apply(). The function syntax looks like:
call( /* object */, /* arguments... */ );
apply(/* object */, /* arguments[] */);
What these functions do is call the function they were inv...
Regular expression to match DNS hostname or IP Address?
...o be escaped with \.
ValidHostnameRegex is valid as per RFC 1123. Originally, RFC 952 specified that hostname segments could not start with a digit.
http://en.wikipedia.org/wiki/Hostname
The original specification of
hostnames in RFC
952,
mandated that labels could not start
with a d...
Google Maps JS API v3 - Simple Multiple Marker Example
...a that I want to cycle through and plot on a map. Seems fairly simple, but all the multi-marker tutorials I have found are quite complex.
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