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Applying a function to every row of a table using dplyr?
...o create an appropriately vectorised function.
R provide pmax which is suitable here, however it also provides Vectorize as a wrapper for mapply to allow you to create a vectorised arbitrary version of an arbitrary function.
library(dplyr)
# use base R pmax (vectorized in C)
iris %>% mutate(max...
How do you do a limit query in JPQL or HQL?
...
// SQL: SELECT * FROM table LIMIT start, maxRows;
Query q = session.createQuery("FROM table");
q.setFirstResult(start);
q.setMaxResults(maxRows);
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How can I SELECT rows with MAX(Column value), DISTINCT by another column in SQL?
My table is:
18 Answers
18
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How do you query for “is not null” in Mongo?
...ta set like my sample) that rather than using an index, MongoDB will use a table scan, even for a potential covered index query. As it turns out that gives me an easy way to illustrate the difference here:
db.foo.find({}, {_id : 0, imageUrl : 1})
{ "imageUrl" : "http://example.com/foo.jpg" }
{ "im...
How to select bottom most rows?
...olumns
FROM
(
SELECT TOP 200
columns
FROM
My_Table
ORDER BY
a_column DESC
) SQ
ORDER BY
a_column ASC
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Can I create a One-Time-Use Function in a Script or Stored Procedure?
...s like:
create procedure #mytemp as
begin
select getdate() into #mytemptable;
end
in an SQL script, but not functions. You could have the proc store it's result in a temp table though, then use that information later in the script ..
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iOS 7 status bar back to iOS 6 default style in iPhone app?
...ontroller and UITabBarController will also try to pad the contentInsets of table views and collection views in its subview hierarchy. It does this in a manner similar to the status bar logic from #4. There is a programmatic way of preventing this, by setting automaticallyAdjustsScrollViewInsets to N...
Comparing two dataframes and getting the differences
... behaviour for pd.concat(), here's the docs pandas.pydata.org/pandas-docs/stable/merging.html
– Thanos
Apr 17 '16 at 18:35
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Difference between shared objects (.so), static libraries (.a), and DLL's (.so)?
...c library(.a) is a library that can be linked directly into the final executable produced by the linker,it is contained in it and there is no need to have the library into the system where the executable will be deployed.
A shared library(.so) is a library that is linked but not embedded in the fin...
Finding duplicate values in a SQL table
...till requires all non-aggregated columns in the GROUP BY.
MySQL is unpredictable and you need sql_mode=only_full_group_by:
GROUP BY lname ORDER BY showing wrong results;
Which is the least expensive aggregate function in the absence of ANY() (see comments in accepted answer).
Oracle isn't mainstr...