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Check if a table exists in Rails
...came explicit regarding tables/views, collectively data sources.
# Tables and views
ActiveRecord::Base.connection.data_sources
ActiveRecord::Base.connection.data_source_exists? 'kittens'
# Tables
ActiveRecord::Base.connection.tables
ActiveRecord::Base.connection.table_exists? 'kittens'
# Views
Ac...
multiple tags
...
Yes, absolutely. You can have multiple header, nav, and footer tags sans penalty.
As long as you're making sure you are using tags semantically and you aren't putting them in invalid places (they're block-level elements, so you can't put them inside an inline element, for exa...
Simultaneously merge multiple data.frames in a list
... issue here is that each data.frame differs in terms of the number of rows and columns, but they all share the key variables (which I've called "var1" and "var2" in the code below). If the data.frames were identical in terms of columns, I could merely rbind , for which plyr's rbind.fill would...
Windows batch: call more than one command in a FOR loop?
Is it possible in Windows batch file to call more than one command in a single FOR loop? Let's say for example I want to print the file name and after delete it:
...
Object initialization syntax
I'm just starting out with F# and I can't find the syntax to do object initialization like in C# 3.
3 Answers
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How do you tell a specific Delayed::Job to run in console?
...te anything even though I've restarted it several times, even kill -9'd it and restarted it. It won't run any jobs.
3 Answe...
Benchmarking (python vs. c++ using BLAS) and (numpy)
I would like to write a program that makes extensive use of BLAS and LAPACK linear algebra functionalities. Since performance is an issue I did some benchmarking and would like know, if the approach I took is legitimate.
...
Show control hierarchy in the WinForms designer
...th a lot of controls on them. Some of those controls have a deep hierarchy and that makes it to hard to select them in the designer.
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Pry: show me the stack
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Use the pry-stack_explorer plugin, it allows you to move up and down the call-stack (with up and down), display the callstack (with show-stack), and so on:
see here:
Frame number: 0/64
From: /Users/johnmair/ruby/rails_projects/personal_site/app/controllers/posts_controller.rb @ lin...
Is there any way in C# to override a class method with an extension method?
...od never takes priority over an instance method with a suitable signature, and never participates in polymorphism (GetHashCode is a virtual method).
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