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In a .csproj file, what is for?
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So then what is difference between a <None> file with "Copy to Output Directory" -> "Copy Always" and a <Content> file with "Copy to Output Directory" -> "Copy Always"?
– hashtable
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What does .SD stand for in data.table in R
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Teams[ , (fkt_idx) := lapply(.SD, as.character), .SDcols = fkt_idx]
And then convert all columns which contain team back to factor:
team_idx = grep('team', names(Teams), value = TRUE)
Teams[ , (team_idx) := lapply(.SD, factor), .SDcols = team_idx]
** Explicitly using column numbers (like DT[ ,...
What's the difference between equal?, eql?, ===, and ==?
...s-specific meaning.
This is the most common comparison, and thus the most fundamental place where you (as the author of a class) get to decide if two objects are "equal" or not.
=== — case equality
For class Object, effectively the same as calling #==, but typically overridden by descendants to ...
Manipulate a url string by adding GET parameters
... parameter is not already in the URL. If the parameter is in a URL already then PHP should take the value of the last occurrence of the parameter in the URL, so the solution of @andrewtweber still works. Yet, I like the following solution stackoverflow.com/a/4101638/99256 better.
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Debugging in Clojure? [closed]
...defn ^:dynamic fib[n] (if (< n 2) n (+ (fib (- n 1)) (fib (- n 2)))))
Then Bob is once again your uncle:
(clojure.tools.trace/dotrace [fib] (fib 3))
TRACE t4328: (fib 3)
TRACE t4329: | (fib 2)
TRACE t4330: | | (fib 1)
TRACE t4330: | | => 1
TRACE t4331: | | (fib 0)
TRACE t4331: | | => 0
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java : convert float to String and String to float
... say this is the least effective method and the worse coding practice but, fun to use,
float val=10.0;
String str=val+"";
the empty quotes, add a null string to the variable str, upcasting 'val' to the string type.
share
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SQLite error 'attempt to write a readonly database' during insert?
...if you are going to do a write operation (INSERT,UPDATE,DELETE,DROP, etc), then the folder the database resides in must have write permissions, as well as the actual database file.
I found this information in a comment at the very bottom of the PDO SQLite driver manual page.
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LAST_INSERT_ID() MySQL
...l be logged out from mysql and logged in again for the second command, and then the variable @last_insert_id isn't set anymore.
My solution is:
lastinsertid=$(mysql -B -N -D "dbname" -e "insert into table1 (myvalue) values ('${foo}');select LAST_INSERT_ID();")
mysql -D "dbname" -e "insert into tabl...
Is #pragma once a safe include guard?
...d if you really need to compile in an environment that doesn't support it, then go ahead and add include guards for that environment.
– Brandin
Jun 22 '14 at 7:45
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PHP/MySQL insert row then get 'id'
...of my table auto increases when I insert a row. I want to insert a row and then get that ID.
10 Answers
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