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Rails where condition using NOT NIL
..., so you really should just use the joins predicate:
Foo.joins(:bar)
Select * from Foo Inner Join Bars ...
But, for the record, if you want a "NOT NULL" condition simply use the not predicate:
Foo.includes(:bar).where.not(bars: {id: nil})
Select * from Foo Left Outer Join Bars on .. WHERE ...
Blocks and yields in Ruby
...y:
days = ["monday", "tuesday", "wednesday", "thursday", "friday"]
# select those which start with 't'
days.select do | item |
item.match /^t/
end
=> ["tuesday", "thursday"]
Or, we can also provide a custom sort algorithm, for instance based on the string size:
days.sort do |x,...
JPA EntityManager: Why use persist() over merge()?
...
I noticed that when I used em.merge, I got a SELECT statement for every INSERT, even when there was no field that JPA was generating for me--the primary key field was a UUID that I set myself. I switched to em.persist(myEntityObject) and got just INSERT statements then...
Can I have multiple primary keys in a single table?
...hese practices, but there is nothing in the relational model that requires selecting a primary key among the candidate keys.
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Disable spell checking on IntelliJ IDEA
...u can either:
Disable spell checking entirely, or
Disable spell checking selectively (e.g. just the code), but enable for some others (e.g. comments).
I'm on MacOS Webstorm (version 2016.1.2). First thing first, go to the "Inspection" pane like this...
Webstorm -> Preferences -> search fo...
Is there a use-case for singletons with database access in PHP?
...all one needs to maintain multiple database connections, multiple database selections, multiple database queries, multiple result sets in a given singleton is just keeping them in variables/arrays in the singleton as long as they are needed. This can be as simple as keeping them in arrays, though yo...
CodeFile vs CodeBehind
...bute of the Page directive or is there a way to create a web project which selects codebehind or codefile, by default, each time a new web page is added?
– Matt W
Nov 5 '09 at 8:42
...
A Better Django Admin ManyToMany Field Widget
...lt models.ManyToManyField widget to be cumbersome to use. It's the HTML select element and if you have a lot of Objects of the "other" model then it's quite impractical to actually find the "other" Objects you want to associate with "this" Object. And if you have a lot of objects of the "other...
Using NumberPicker Widget with Strings
...wrap true or false, try it you will know the difference
pickers.setWrapSelectorWheel(false);
//create button to test selected text string
btnPicker.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
//get position (int)...
Can't execute jar- file: “no main manifest attribute”
...o specify the Application's entry point in eclipse.
When you say Export,
Select Jar and next
[ give it a name in the next window ] and next
and next again
and you'll see " Select the class of the application entry point".
Just pick a class and Eclipse will automatically build a cool MANIFEST....