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Rails find_or_create_by more than one attribute?
... you aren't searching by.
Assuming:
class GroupMember < ActiveRecord::Base
validates_presence_of :name
end
then
GroupMember.where(:member_id => 4, :group_id => 7).first_or_create { |gm| gm.name = "John Doe" }
will create a new GroupMember with the name "John Doe" if it doesn't fi...
Where can I learn how to write C code to speed up slow R functions? [closed]
...can judge for yourself what you find more complicated, obfuscated, etc ... based on a few examples. This function creates a character vector using the C API:
SEXP foobar(){
SEXP ab;
PROTECT(ab = allocVector(STRSXP, 2));
SET_STRING_ELT( ab, 0, mkChar("foo") );
SET_STRING_ELT( ab, 1, mkChar(...
npm install vs. update - what's the difference?
...
@Borek npm update will update to the latest version based on your package.json, not regardless of it. If you have "express": "3.x" and you are on version 3.1.0, it will update to the latest 3.x tag. If there is a 4.x version, it will not install the latest.
...
JPA : How to convert a native query result set to POJO class collection
...ult set mapping (which defines the mapping of the data returned by the database to your POJOs). Write your POJO class to refer to (not included here for brevity). Last but not least: create a method in a DAO (for example) to call the query. This worked for me in a dropwizard (1.0.0) app.
First decl...
extract part of a string using bash/cut/split
...ce means shortest and two instances means longest.
You can get substrings based on position using numbers:
${MYVAR:3} # Remove the first three chars (leaving 4..end)
${MYVAR::3} # Return the first three characters
${MYVAR:3:5} # The next five characters after removing the first 3 (chars 4-9)
...
Can I use my existing git repo with openshift?
...epo-url>, here is what I would do:
Create a new local branch openshift based on the master branch.
git checkout -b openshift
You could make some commits on the branch openshift such as your app deployment configurations.
Then, push the current branch to the remote ref matching master in the O...
Why use @PostConstruct?
.... If i wish to initialise an inputtext field with a value fetched from database, I am able to do it with the help of PostConstruct, but fails when try to do the same inside the constructor. I have this requirement to initialise without the use of PostContruct. If you have time, can you please answer...
Django - how to create a file and save it to a model's FileField?
... must be an instance of either django.core.files.File or django.core.files.base.ContentFile (see given links to manual for the details). The two choices boil down to:
# Using File
f = open('/path/to/file')
self.license_file.save(new_name, File(f))
# Using ContentFile
self.license_file.save(new_name...
Fragment or Support Fragment?
...cations with a good deal of complexity and/or your overall architecture is based on either a tabbed layout or uses the navigation drawer.
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'const string' vs. 'static readonly string' in C#
...r all). Note this even affects private const fields because you might have base and subclass in different assemblies and private fields are inherited.
Static fields are tied to the type they are declared within. They are used for representing values that need to be the same for all instances of a g...