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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 ...
How to change the blue highlight color of a UITableViewCell?
I'm wondering how to change the blue highlight/selection color of a UITableViewCell , any ideas?
11 Answers
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Avoid duplicates in INSERT INTO SELECT query in SQL Server
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Using NOT EXISTS:
INSERT INTO TABLE_2
(id, name)
SELECT t1.id,
t1.name
FROM TABLE_1 t1
WHERE NOT EXISTS(SELECT id
FROM TABLE_2 t2
WHERE t2.id = t1.id)
Using NOT IN:
INSERT INTO TABLE_2
(id, name)
SELECT t1.id,
t1....
How to check date of last change in stored procedure or function in SQL server
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SELECT name, create_date, modify_date
FROM sys.objects
WHERE type = 'P'
ORDER BY modify_date DESC
The type for a function is FN rather than P for procedure. Or you can filter on the name column.
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Inserting a text where cursor is using Javascript/jquery
...ar scrollPos = txtarea.scrollTop;
var strPos = 0;
var br = ((txtarea.selectionStart || txtarea.selectionStart == '0') ?
"ff" : (document.selection ? "ie" : false));
if (br == "ie") {
txtarea.focus();
var range = document.selection.createRange();
range.moveStart('characte...
Allowed characters in Linux environment variable names
What characters are allowed in Linux environment variable names? My cursory search of man pages and the web did only produce information about how to work with variables, but not which names are allowed.
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How to get equal width of input and select fields
On the form, I have one select and two input fields. These elements are vertically aligned. Unfortunately, I can't get equal width of these elements.
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Run an app on a multiple devices automatically in Android Studio
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if you shold shift, select all devices, and you click "Run on the same device next time", even if it doesn't' put plural "devices" it will automatically run on all the next time.
– OWADVL
Oct 28 '14 at 10:2...
Android - Set max length of logcat messages
...e { Log.v(TAG, sb); } to also print the log when the message is <= 4000 chars long
– Bojan Radivojevic Bomber
Apr 26 '14 at 21:45
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How to quickly open a file in Visual Studio 2012
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This would be perfect if it would clear the selection after opening the file. As it is, having to manually clear it with the mouse makes it nearly useless. :-( I want a sublime text style onebox open file/search symbol/goto line addin for VS.
– Ch...