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How to create a MySQL hierarchical recursive query
... parent_id
from products
where parent_id = 19
union all
select p.id,
p.name,
p.parent_id
from products p
inner join cte
on p.parent_id = cte.id
)
select * from cte;
The value specified in parent_id = 19 should be set to the...
ERROR 1396 (HY000): Operation CREATE USER failed for 'jack'@'localhost'
...be stupid" and to use REVOKE and DROP USER to do it right. I'm indebted to all three answers (this one just happens to be the one that bailed me out of my present predicament).
– Russ Bateman
Apr 5 '11 at 17:05
...
Calling filter returns [duplicate]
...ten) want to do the filtering in a lazy sense -- You don't need to consume all of the memory to create a list up front, as long as the iterator returns the same thing a list would during iteration.
If you're familiar with list comprehensions and generator expressions, the above filter is now (alm...
SVN command to delete all locally missing files
In SVN is there a command I can use to delete all locally missing files in a directory?
12 Answers
...
ASP.NET MVC: Custom Validation by DataAnnotation
...ationContext.ObjectInstance, null)).OfType<string>();
var totalLength = values.Sum(x => x.Length) + Convert.ToString(value).Length;
if (totalLength < this.MinLength)
{
return new ValidationResult(this.FormatErrorMessage(validationContext.DisplayName));...
Who architected / designed C++'s IOStreams, and would it still be considered well-designed by today'
... sign of quality design.
IOStreams have a checkered history. They are actually a reworking of an earlier streams library, but were authored at a time when many of today's C++ idioms didn't exist, so the designers didn't have the benefit of hindsight. One issue that only became apparent over time wa...
Trim spaces from end of a NSString
...substringWithRange:NSMakeRange(location, i - location)];
}
So now just call it. Supposing you have a string that has spaces on the front and spaces on the end and you just want to remove the spaces on the end, you can call it like this:
NSString *oneTwoThree = @" TestString ";
NSString *resul...
What's the fastest algorithm for sorting a linked list?
...; there are no pathological cases.
Auxiliary storage requirement is small and constant (i.e. a few variables within the sorting routine). Thanks to the inherently different behaviour of linked lists from arrays, this Mergesort implementation avoids the O(N) auxiliary storage cost normally assoc...
in_array() and multidimensional array
...sive (hence the _r, analogous to print_r(), for example). It descends into all nested arrays to search for the value until there are no more arrays to be found. This way, you can search through arrays of arbitrary complexity instead of just two levels deep.
– jwueller
...
Why no generics in Go?
... id types. Type information is preserved and can be "cast" (asserted, actually) back to its concrete type. Get the gritty details here: golang.org/ref/spec#Type_assertions
– tbone
Aug 25 '13 at 20:50
...