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How do you write a migration to rename an ActiveRecord model and its table in Rails?
...tion::CommandRecorder knows how to reverse rename_table migrations, so you can do this:
class RenameOldTableToNewTable < ActiveRecord::Migration
def change
rename_table :old_table_name, :new_table_name
end
end
(You still have to go through and manually rename your files.)
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Are class names in CSS selectors case sensitive?
I keep reading everywhere that CSS is not case sensitive, but I have this selector
4 Answers
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When to add what indexes in a table in Rails
...add "index" to all the foreign keys like "xxx_id"?
It would be better, because it accelerates the search in sorting in this column. And Foreign keys are something searched for a lot.
Since Version 5 of rails the index will be created automatically, for more information see here.
Should I add ...
Is GridFS fast and reliable enough for production?
... a new website and I want to use GridFS as storage for all user uploads, because it offers a lot of advantages compared to a normal filesystem storage.
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How does git compute file hashes?
...
You can also compare this to the output of echo 'Hello, World!' | git hash-object --stdin. Optionally you can specify --no-filters to make sure no crlf conversion happens, or specify --path=somethi.ng to let git use the filter sp...
Configuring Log4j Loggers Programmatically
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You can add/remove Appender programmatically to Log4j:
ConsoleAppender console = new ConsoleAppender(); //create appender
//configure the appender
String PATTERN = "%d [%p|%c|%C{1}] %m%n";
console.setLayout(new PatternLa...
Is a Python list guaranteed to have its elements stay in the order they are inserted in?
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what if I return a local list from a function and use that in the calling function. That is def fn_1(): lst = [] lst.append(1) lst.append(2) return lst and def fn_2(): print(fn_1()) Will the order be same ALWAYS irrespective of how many times or ...
Is it safe to remove selected keys from map within a range loop?
How can one remove selected keys from a map?
Is it safe to combine delete() with range, as in the code below?
4 Answers
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SVN how to resolve new tree conflicts when file is added on two branches
...sting versioned file.
This should be a tree conflict on the file of the 'local obstruction, incoming add upon merge' variety. Fixed expectations in r35341.
(This is also called "evil twins" in ClearCase by the way):
a file is created twice (here "added" twice) in two different branches, creating tw...
What are the differences between Clojure, Scheme/Racket and Common Lisp?
I know they are dialects of the same family of language called lisp, but what exactly are the differences? Could you give an overview, if possible, covering topics such as syntax, characteristics, features and resources.
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