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How to drop columns by name in a data frame
..."z","u"))]
x y
1 1 2
2 2 3
3 3 4
4 4 5
5 5 6
Or, much simpler, use the select argument of the subset function : you can then use the - operator directly on a vector of column names, and you can even omit the quotes around the names !
R> subset(df, select=-c(z,u))
x y
1 1 2
2 2 3
3 3 4
4 4 ...
Can I combine :nth-child() or :nth-of-type() with an arbitrary selector?
Is there a way to select every nth child that matches (or does not match) an arbitrary selector ? For example, I want to select every odd table row, but within a subset of the rows:
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How do I disable text selection with CSS or JavaScript? [duplicate]
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<div
style="-moz-user-select: none; -webkit-user-select: none; -ms-user-select:none; user-select:none;-o-user-select:none;"
unselectable="on"
onselectstart="return false;"
onmousedown="return false;">
Blabla
</div>
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Is it possible to have a multi-line comments in R? [duplicate]
I found this old thread (from over a year ago), which explains how come R doesn't support a multi-line comments (like /* comment */ of PHP, for example).
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Entity Framework and SQL Server View
...mn as a primary key, use NULLIF.
An easy way to apply this is to wrap the select statement of your view in another select.
Example:
SELECT
ISNULL(MyPrimaryID,-999) MyPrimaryID,
NULLIF(AnotherProperty,'') AnotherProperty
FROM ( ... ) AS temp
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How to check if an option is selected?
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UPDATE
A more direct jQuery method to the option selected would be:
var selected_option = $('#mySelectBox option:selected');
Answering the question .is(':selected') is what you are looking for:
$('#mySelectBox option').each(function() {
if($(this).is(':selected')) ....
How to remove application from app listings on Android Developer Console
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Select Store Presense then Pricing Distribution and select Unpublish from App Availability.
Google's help for this is here: https://support.google.com/googleplay/android-developer/answer/113476#unpublish (as of Feb-2020)
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How to trim a string in SQL Server before 2017?
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SELECT LTRIM(RTRIM(Names)) AS Names FROM Customer
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Computed / calculated / virtual / derived columns in PostgreSQL
...y as column?
The expression (looking like a column) is not included in a SELECT * FROM tbl, though. You always have to list it explicitly.
Can also be supported with a matching expression index - provided the function is IMMUTABLE. Like:
CREATE FUNCTION col(tbl) ... AS ... -- your computed expr...
How to open existing project in Eclipse
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Project > Import > General > Select Root Directory > (do NOT select copy projects into workspace). This is useful if you use Eclipse outside scope of Java project as well, such as Ruby projects or C projects.
– JohnMerlino
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