大约有 48,000 项符合查询结果（耗时：0.0507秒） [XML]
Pass a data.frame column name to a function
...(x[,column])
}
fun1(df, "B", max)
Alternatively, using [[ also works for selecting a single column at a time:
df <- data.frame(A=1:10, B=2:11, C=3:12)
fun1 <- function(x, column){
max(x[[column]])
}
fun1(df, "B")
...
How can I set a custom date time format in Oracle SQL Developer?
...veloper's menu go to: Tools > Preferences.
From the Preferences dialog, select Database > NLS from the left panel.
From the list of NLS parameters, enter DD-MON-RR HH24:MI:SS into the Date Format field.
Save and close the dialog, done!
Here is a screenshot:
...
Is it possible to open a Windows Explorer window from PowerShell?
...tion looking for a way to open an Explorer window from PowerShell and also select a file. I'm adding this answer in case others come across it for the same reason.
To launch Explorer and select a file, use Invoke-Expression:
Invoke-Expression "explorer '/select,$filePath'"
There are probably oth...
What is syntax for selector in CSS for next element?
...
This is called the adjacent sibling selector, and it is represented by a plus sign...
h1.hc-reform + p {
clear:both;
}
Note: this is not supported in IE6 or older.
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Addressing localhost from a VirtualBox virtual machine [closed]
...-> Network -> Host-only Networks -> click the "+" icon. Click OK.
Select your box and click the "Settings" icon -> Network -> Adapter 2 -> On the "Attached to:" dropdown, select "Host-only Adapter" and your network (vboxnet0) should show up below by default. Click OK.
Once you star...
AppStore - App status is ready for sale, but not in app store
... and Availability.
Then I waited 1 hour.
Then I ticked All Territories Selected again.
After the app came available for download again the version number was updated.
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How to set initial value and auto increment in MySQL?
...r) values("kowalski's nuclear reactor.");
Step 4, interpret the output:
select * from penguins
prints:
'1001', 'We need more power!'
'1002', 'Time to fire up'
'1003', 'kowalski\'s nuclear reactor'
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Is there a Boolean data type in Microsoft SQL Server like there is in MySQL? [duplicate]
...compared using a comparison operator such as =, <> or IS NULL. e.g.
SELECT
a.answer_body
FROM answers AS a
WHERE a.is_accepted = 0;
From a formatting perspective, a bit value is typically displayed as 0 or 1 in client software. When a more user-friendly format is required, and it can't ...
Adding external library in Android studio
... Found ass module dependency but then I got dialog "Choose Modules\nSelect the modules the current module should depend on:\nNothing to show\n[Ok] [Cancel]". Not able to select downloaded library.
– David162795
Aug 1 '18 at 10:48
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Can I find events bound on an element with jQuery?
... I'm attempting your solution but still getting undefined returned for the selector. I used $('#elem').bind('click', function() {}); if that would make a difference.
– Marcus
Oct 19 '12 at 2:13
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