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How do I handle too long index names in a Ruby on Rails ActiveRecord migration?
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Provide the :name option to add_index, e.g.:
add_index :studies,
["user_id", "university_id", "subject_name_id", "subject_type_id"],
:unique => true,
:name => 'my_index'
If using the :index option on references in a create_table block, it t...
How to copy a directory using Ant
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@s1n This commands only copies all the contents of src_dir to ../new/dir and not the src_dir. How do we copy src_dir (directory) to another location?
– Pipalayan Nayak
Dec 3 '11 at 19:24
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Most efficient way to reverse a numpy array
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When you create reversed_arr you are creating a view into the original array. You can then change the original array, and the view will update to reflect the changes.
Are you re-creating the view more often than you need to? You should be able to...
How do I “un-revert” a reverted Git commit?
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Please note this will remove all changes in working tree and index. Use git stash to save any changes you don't wan't to lose.
– zpon
Aug 30 '16 at 5:37
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Correct way to define Python source code encoding
...f you want to be 100% python-docs-recommendation-compatible.
More specifically, you need to use whatever is recognized by Python and the specific editing software you use (if it needs/accepts anything at all). E.g. the coding form is recognized (out of the box) by GNU Emacs but not Vim (yes, withou...
Getting an “ambiguous redirect” error
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Bash can be pretty obtuse sometimes.
The following commands all return different error messages for basically the same error:
$ echo hello >
bash: syntax error near unexpected token `newline`
$ echo hello > ${NONEXISTENT}
bash: ${NONEXISTENT}: ambiguous redirect
$ echo hello ...
Should I use char** argv or char* argv[]?
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As you are just learning C, I recommend you to really try to understand the differences between arrays and pointers first instead of the common things.
In the area of parameters and arrays, there are a few confusing rules that should be clear before going on. First, what ...
Secure random token in Node.js
...oding in node is not url-safe, it includes / and + instead of - and _ . Therefore, the easiest way to generate such token I've found is
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Storing Images in PostgreSQL
...we see that image sizes, and number of images, are growing and growing, in all applications...
We need some distinction between "original image" and "processed image", like thumbnail.
As Jcoby's answer says, there are two options, then, I recommend:
use blob (Binary Large OBject): for original imag...
What does DIM stand for in Visual Basic and BASIC?
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Dim originally (in BASIC) stood for Dimension, as it was used to define the dimensions of an array.
(The original implementation of BASIC was Dartmouth BASIC, which descended from FORTRAN, where DIMENSION is spelled out.)
Nowadays, D...