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SQLite: How do I save the result of a query as a CSV file?
...
All the existing answers only work from the sqlite command line, which isn't ideal if you'd like to build a reusable script. Python makes it easy to build a script that can be executed programatically.
import pandas as pd
im...
Simplest way to do a recursive self-join?
...e ultimate ancestors in your chain, change it as appropriate
UNION ALL
SELECT m.*
FROM mytable m
JOIN q
ON m.parentID = q.PersonID
)
SELECT *
FROM q
By adding the ordering condition, you can preserve the tree order:
WITH q AS
...
Are there benefits of passing by pointer over passing by reference in C++?
...ect", then use a pointer instead of a reference.
Also, passing by pointer allows you to explicitly see at the call site whether the object is passed by value or by reference:
// Is mySprite passed by value or by reference? You can't tell
// without looking at the definition of func()
func(mySpri...
Inheriting from a template class in c++
... way you speak about them determines the way to think about them.
Specifically, Area is not a template class, but a class template. That is, it is a template from which classes can be generated. Area<int> is such a class (it's not an object, but of course you can create an object from that cl...
How can I remove specific rules from iptables?
...
If you have several rules of a kind, it will not remove all of them.
– ETech
Mar 27 '14 at 8:22
4
...
Calculate MD5 checksum for a file
... {
return md5.ComputeHash(stream);
}
}
(I believe that actually the MD5 implementation used doesn't need to be disposed, but I'd probably still do so anyway.)
How you compare the results afterwards is up to you; you can convert the byte array to base64 for example, or compare the by...
What is the difference between HAVING and WHERE in SQL?
...nt(1)
From Address
Where State = 'MA'
Group By City
Gives you a table of all cities in MA and the number of addresses in each city.
This code:
select City, CNT=Count(1)
From Address
Where State = 'MA'
Group By City
Having Count(1)>5
Gives you a table of cities in MA with more than 5 address...
Why are dashes preferred for CSS selectors / HTML attributes?
...re separated with underscore and there were no stops.
Also, using hyphens allows you to take advantage of the |= attribute selector, which selects any element containing the text, optionally followed by a dash:
span[class|="em"] { font-style: italic; }
This would make the following HTML elements...
How to reverse a string in Go?
...size of the input in bytes. It does not correspond to its length. - Not all utf8's runes are of the same size. It can be either 1, 2, 4, or 8. - You should use unicode/ut8 package's method RuneCountInString to get the length of the rune.
– Anvesh Checka
M...
What is the difference between LL and LR parsing?
...te by hand, but they are less powerful than LR parsers and accept a much smaller set of grammars than LR parsers do. LR parsers come in many flavors (LR(0), SLR(1), LALR(1), LR(1), IELR(1), GLR(0), etc.) and are far more powerful. They also tend to have much more complex and are almost always gene...