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Creating an R dataframe row-by-row
...d like to construct a dataframe row-by-row in R. I've done some searching, and all I came up with is the suggestion to create an empty list, keep a list index scalar, then each time add to the list a single-row dataframe and advance the list index by one. Finally, do.call(rbind,) on the list.
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What is the difference between Scope_Identity(), Identity(), @@Identity, and Ident_Current()?
I know Scope_Identity() , Identity() , @@Identity , and Ident_Current() all get the value of the identity column, but I would love to know the difference.
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'float' vs. 'double' precision
... in C use IEEE 754 encoding.
This type of encoding uses a sign, a significand, and an exponent.
Because of this encoding, many numbers will have small changes to allow them to be stored.
Also, the number of significant digits can change slightly since it is a binary representation, not a decimal ...
SQL Server Script to create a new user
...I think that you may be a bit confused about the difference between a User and a Login. A Login is an account on the SQL Server as a whole - someone who is able to log in to the server and who has a password. A User is a Login with access to a specific database.
Creating a Login is easy and must ...
Embed git commit hash in a .Net dll
... answered Feb 28 '13 at 19:14
HandcraftsmanHandcraftsman
6,15722 gold badges3636 silver badges3333 bronze badges
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get NSDate today, yesterday, this Week, last Week, this Month, last Month… variables
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Adapted from the Date and Time Programming Guide:
// Right now, you can remove the seconds into the day if you want
NSDate *today = [NSDate date];
// All intervals taken from Google
NSDate *yesterday = [today dateByAddingTimeInterval: -86400.0];...
What is the best way to prevent session hijacking?
... when a user visits one of your "sensitive" areas, redirect them to HTTPS, and check for the presence of that secure cookie. A real user will have it, a session hijacker will not.
EDIT: This answer was originally written in 2008. It's 2016 now, and there's no reason not to have SSL across your enti...
Linq to Entities join vs groupjoin
... [b1, b2]
C []
So Join produces a flat (tabular) result of parent and child values.
GroupJoin produces a list of entries in the first list, each with a group of joined entries in the second list.
That's why Join is the equivalent of INNER JOIN in SQL: there are no entries for C. While Group...
What do the numbers in a version typically represent (i.e. v1.9.0.1)?
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I'm trying to understand this system. So here is a question: What if a new release has a feature and a bug fix, what should I increment?
– iTurki
Jul 16 '13 at 19:36
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Set a DateTime database field to “Now”
...ateTime.Now will do this or If I should first convert the date to a string and then add it to the request ?
– Thibault Witzig
Dec 20 '10 at 9:41
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