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How to select a CRAN mirror in R
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Repository selection screen cannot be shown on your system (OS X), since OS X no longer includes X11. R tries to show you the prompt through X11. Install X11 from http://xquartz.macosforge.org/landing/. Then run the install command. The...
How do I compare two files using Eclipse? Is there any option provided by Eclipse?
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To compare two files in Eclipse, first select them in the Project Explorer / Package Explorer / Navigator with control-click. Now right-click on one of the files, and the following context menu will appear. Select Compare With / Each Other.
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Count(*) vs Count(1) - SQL Server
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The optimizer recognizes it for what it is: trivial.
The same as EXISTS (SELECT * ... or EXISTS (SELECT 1 ...
Example:
SELECT COUNT(1) FROM dbo.tab800krows
SELECT COUNT(1),FKID FROM dbo.tab800krows GROUP BY FKID
SELECT COUNT(*) FROM dbo.tab800krows
SELECT COUNT(*),FKID FROM dbo.tab800krows GROU...
SQL Server insert if not exists best practice
...sert Competitors where doesn't already exist":
INSERT Competitors (cName)
SELECT DISTINCT Name
FROM CompResults cr
WHERE
NOT EXISTS (SELECT * FROM Competitors c
WHERE cr.Name = c.cName)
share
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An explicit value for the identity column in table can only be specified when a column list is used
...tead of
SET IDENTITY_INSERT archive_table ON;
INSERT INTO archive_table
SELECT *
FROM source_table;
SET IDENTITY_INSERT archive_table OFF;
you need to write
SET IDENTITY_INSERT archive_table ON;
INSERT INTO archive_table (field1, field2, ...)
SELECT field1, field2, ...
FROM source_table;...
How do I set up IntelliJ IDEA for Android applications?
...Program Files\Java\jdk{version}
Choose a New platform ( if there's not one selected ) , the SDK platform is the android platform at C:\Program Files\Android\android-sdk-windows.
Choose the android version.
Now you can write your program.
Compiling:
Near the Run button you need to select the drop...
How do I open links in Visual Studio in my web browser and not in Visual Studio?
...swer.
Sub OpenURLInChrome()
'copy to end of line
DTE.ActiveDocument.Selection.EndOfLine(True)
'set var
Dim url As String = DTE.ActiveDocument.Selection.Text
'launch chrome with url
System.Diagnostics.Process.Start( _
Environment.GetFolderPath(Environment.SpecialFolder.Local...
How do I find duplicates across multiple columns?
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Duplicated id for pairs name and city:
select s.id, t.*
from [stuff] s
join (
select name, city, count(*) as qty
from [stuff]
group by name, city
having count(*) > 1
) t on s.name = t.name and s.city = t.city
...
Get list of databases from SQL Server
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Execute:
SELECT name FROM master.sys.databases
This the preferred approach now, rather than dbo.sysdatabases, which has been deprecated for some time.
Execute this query:
SELECT name FROM master.dbo.sysdatabases
or if you pref...
TSQL Pivot without aggregate function
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yes, but why !!??
Select CustomerID,
Min(Case DBColumnName When 'FirstName' Then Data End) FirstName,
Min(Case DBColumnName When 'MiddleName' Then Data End) MiddleName,
Min(Case DBColumnName When 'LastName' Then Data End) LastNa...