大约有 13,000 项符合查询结果（耗时：0.0323秒） [XML]
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 ...
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...
Convert Month Number to Month Name Function in SQL
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A little hacky but should work:
SELECT DATENAME(month, DATEADD(month, @mydate-1, CAST('2008-01-01' AS datetime)))
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Xcode iOS project only shows “My Mac 64-bit” but not simulator or device
...duct->Scheme->Edit Scheme...), and for some reason no executable was selected. I chose my app, saved and now I have my simulator and device options back.
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Strings as Primary Keys in SQL Database [closed]
... Also keep in mind that there's often a very big difference between a CHAR and a VARCHAR when doing index comparisons
– Tom H
Feb 5 '09 at 20:42
7
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How can I change IIS Express port for a site
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In Solution Explorer, right-click the name of the application and then select Properties.
Click the Web tab.
In the Servers section, under Use Local IIS Web server, in the Project URL box change the port number.
To the right of the Project URL box, click Create Virtual Directory, and then ...
The multi-part identifier could not be bound
...tion is specified in the WHERE clause).
Here's an outline of your query:
SELECT
…
FROM a, b LEFT JOIN dkcd ON …
WHERE …
You are probably expecting it to behave like this:
SELECT
…
FROM (a, b) LEFT JOIN dkcd ON …
WHERE …
that is, the combination of tables a and b is joined with...
Jump to matching XML tags in Vim
...n do this without additional plugins:
place cursor on the tag
vat - will select the (outer) tag and place cursor on the end
once you've got your selection you can toggle between the top and bottom with o (update based on Michael Gruber's note)
c - change or, y - copy or, escape for leaving visual ...
Execute Insert command and return inserted Id in Sql
...md=new SqlCommand("INSERT INTO Mem_Basic(Mem_Na,Mem_Occ) VALUES(@na,@occ);SELECT SCOPE_IDENTITY();",con))
{
cmd.Parameters.AddWithValue("@na", Mem_NA);
cmd.Parameters.AddWithValue("@occ", Mem_Occ);
con.Open();
int modified = Convert.ToInt32(cmd.ExecuteScalar());...
Serialize an object to string
...and NewLineOnAttributes = false did the job.
– Lee Richardson
Nov 17 '14 at 15:37
Thanks @LeeRichardson - I needed to ...