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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,...
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)...
Difference between binary semaphore and mutex
...perspective, mutex are more like state-pattern where the algorithm that is selected by the state can change the state. The binary-semaphore are more like strategy pattern where the external algorithm can change the state and eventually the algorithm/strategy selected to run.
– ...
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
...
How can I enable the Windows Server Task Scheduler History recording?
...plication and Service Logs then Microsoft, Windows, TaskScheduler and then select Operational.
You should have Actions showing in the preview pane with two sections - Operational and below that Event nnn, TaskScheduler. One of the items listed in the Operational section should be Properties. Click ...
How can I make a clickable link in an NSAttributedString?
...operties
}
Make Sure that the NSTextField's Behavior attribute is set as Selectable.
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How do you load custom UITableViewCells from Xib files?
...iles, as prototype cells.
If you need to attach a class to them, you can select the cell prototype and add the corresponding class (must be a descendant of UITableViewCell, of course).
Dequeue
And later on, dequeued using (swift 3.0):
override func tableView(tableView: UITableView, cellForRowA...
The backend version is not supported to design database diagrams or tables
...se the version designed for your database version. You can use the command select @@version to check which version of sql server you are actually using. This version is reported in a way that is easier to interpret than that shown in the Help About in SSMS.
Using a newer version of SSMS than your...
What are advantages of Artificial Neural Networks over Support Vector Machines? [closed]
..., an SVM (at least a kernelized one) consists of a set of support vectors, selected from the training set, with a weight for each. In the worst case, the number of support vectors is exactly the number of training samples (though that mainly occurs with small training sets or in degenerate cases) an...