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Eclipse add Tomcat 7 blank server name
...at 7 in my Eclipse in Ubuntu. When I click "Add new server" in Eclipse and select "Tomcat v7.0 Server", the field "Server Name" is blank and I cannot type in anything in that textbox as shown below:
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Delete sql rows where IDs do not have a match from another table
...HERE f.id IS NULL
Using NOT EXISTS:
DELETE FROM BLOB
WHERE NOT EXISTS(SELECT NULL
FROM FILES f
WHERE f.id = fileid)
Using NOT IN:
DELETE FROM BLOB
WHERE fileid NOT IN (SELECT f.id
FROM FILES f)
Warning
Whenever possible, per...
Compare two data.frames to find the rows in data.frame 1 that are not present in data.frame 2
...ata.frame(a = 1:3, b=letters[1:3])
require(sqldf)
a1NotIna2 <- sqldf('SELECT * FROM a1 EXCEPT SELECT * FROM a2')
And the rows which are in both data frames:
a1Ina2 <- sqldf('SELECT * FROM a1 INTERSECT SELECT * FROM a2')
The new version of dplyr has a function, anti_join, for exactly the...
How to get TimeZone from android mobile?
...ndar.getInstance();
TimeZone tz = cal.getTimeZone();
It will return user selected timezone.
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How to resize the iPhone/iPad Simulator?
...
Xcode 9.x :
Select Simulator
Goto Window tab
Select Physical Size option (cmd + 1)
Now if this dosen’t make size as per your interest then follow below steps :
Select Simulator
Goto edge of simulator. This will convert your curso...
Automatic Preferred Max Layout Width is not available on iOS versions prior to 8.0
... my steps below.
In xCode's Issue Navigator right click on the error and select "Reveal In Log". (Note: @Sam suggests below, look in xCode's report navigator. Also @Rivera notes in the comments that "As of Xcode 6.1.1, clicking on the warning will automatically open and highlight the conflicting l...
When and why are database joins expensive?
...s back to mitigating the size of the working set. Joins involving properly selected keys with correctly set up indexes are cheap, not expensive, because they allow significant pruning of the result before the rows are materialised.
Materialising the result involves bulk disk reads which are the mo...
What does an Asterisk (*) do in a CSS selector?
...
It is a wildcard, this means it will select all elements within that portion of the DOM.
For example, if I want apply margin to every element on my entire page you can use:
* {
margin: 10px;
}
You can also use this within sub-selections, for example the ...
What are the various “Build action” settings in Visual Studio project properties and what do they do
... as a default... I'm referring to the BuildAction property for each file selected in Solution Explorer. There are a number of options and it's difficult to know what each one of them will do.
...
Manually put files to Android emulator SD card
... Card through the Android Perspective (it is called DDMS in Eclipse). Just select the Emulator in the left part of the screen and then choose the File Explorer tab. Above the list with your files should be two symbols, one with an arrow pointing at a phone, clicking this will allow you to choose a f...