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How to UPSERT (MERGE, INSERT … ON DUPLICATE UPDATE) in PostgreSQL?
A very frequently asked question here is how to do an upsert, which is what MySQL calls INSERT ... ON DUPLICATE UPDATE and the standard supports as part of the MERGE operation.
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Iterate all files in a directory using a 'for' loop
...the files (and only the files) in the current directory:
for /r %i in (*) do echo %i
Also if you run that command in a batch file you need to double the % signs.
for /r %%i in (*) do echo %%i
(thanks @agnul)
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Best practices with STDIN in Ruby?
...t gets all input from named files or all from STDIN.
ARGF.each_with_index do |line, idx|
print ARGF.filename, ":", idx, ";", line
end
# print all the lines in every file passed via command line that contains login
ARGF.each do |line|
puts line if line =~ /login/
end
Thank goodness we did...
How do I run only specific tests in Rspec?
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It isn't easy to find the documentation, but you can tag examples with a hash. Eg.
# spec/my_spec.rb
describe SomeContext do
it "won't run this" do
raise "never reached"
end
it "will run this", :focus => true do
1.should == 1
end
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do { … } while (0) — what is it good for? [duplicate]
...dition)
FOO(x);
else // syntax error here
...;
Even using braces doesn't help:
#define FOO(x) { foo(x); bar(x); }
Using this in an if statement would require that you omit the semicolon, which is counterintuitive:
if (condition)
FOO(x)
else
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If you define FOO like this:
#...
How do I put variables inside javascript strings?
That's how you do it in python. How can you do that in javascript/node.js?
13 Answers
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How do I create a message box with “Yes”, “No” choices and a DialogResult?
...plish this. It is simple, but since there is no DialogResult returned, how do I retrieve the result?
11 Answers
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How do I return early from a rake task?
I have a rake task where I do some checks at the beginning, if one of the checks fails I would like to return early from the rake task, I don't want to execute any of the remaining code.
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Iterate through every file in one directory
How do I write a loop in ruby so that I can execute a block of code on each file?
8 Answers
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Asynchronous Requests with Python requests
I tried the sample provided within the documentation of the requests library for python.
12 Answers
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