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Pass a data.frame column name to a function
...want to save the user from typing all those quotes, one option might be to convert bare, unquoted column names to strings using deparse(substitute()):
new_column2 <- function(df,col_name,col1,col2){
col_name <- deparse(substitute(col_name))
col1 <- deparse(substitute(col1))
col...
Check if table exists and if it doesn't exist, create it in SQL Server 2008
...LECT * FROM sys.objects
WHERE object_id = OBJECT_ID(N'[dbo].[YourTable]') AND type in (N'U'))
BEGIN
CREATE TABLE [dbo].[YourTable](
....
....
....
)
END
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Why does (i
... j is evaluated to true, because auto unboxing happens for int
comparisons and then both i and j hold the default value, 0.
j <= i is evaluated to true because of the above reason.
i != j is evaluated to true, because both i and j are
different objects. And while comparing objects, there isn't an...
Insert results of a stored procedure into a temporary table
...a SELECT * INTO [temp table] FROM [stored procedure] ? Not FROM [Table] and without defining [temp table] ?
30 Answers
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Select a Dictionary with LINQ
I have used the "select" keyword and extension method to return an IEnumerable<T> with LINQ, but I have a need to return a generic Dictionary<T1, T2> and can't figure it out. The example I learned this from used something in a form similar to the following:
...
Differences between Perl and PHP [closed]
...rators. In Perl, if you use <, >, ==, !=, <=>, and so on, Perl converts both operands to numbers. If you want to convert as strings instead, you have to use lt, gt, eq, ne, cmp (the respective equivalents of the operators listed previously). Examples where this will really get you:
if (...
How to overload std::swap()
std::swap() is used by many std containers (such as std::list and std::vector ) during sorting and even assignment.
4 A...
private[this] vs private
...t very rich Java background I learnt to close everything (make it private) and open (provide accessors) if necessary. Scala introduces even more strict access modifier. Should I always use it by default? Or should I use it only in some specific cases where I need to explicitly restrict changing fiel...
How to intercept click on link in UITextView?
...characterRange interaction:(UITextItemInteraction)interaction;
From ios7 and Later UITextView has the delegate method:
- (BOOL)textView:(UITextView *)textView shouldInteractWithURL:(NSURL *)URL inRange:(NSRange)characterRange *NS_DEPRECATED_IOS(7_0, 10_0, "Use textView:shouldInteractWithURL:inRan...
Compelling examples of custom C++ allocators?
...
std::vector<T,tbb::scalable_allocator<T> >
(this is a quick and convenient way of switching the allocator to use TBB's nifty thread-private heaps; see page 7 in this document)
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