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Can a foreign key be NULL and/or duplicate?
.... So your proposal table would have two foreign keys, one with the client ID and one with the sales rep ID. However, at the time the record is created, a sales rep is not always assigned (because no one is free to work on it yet), so the client ID is filled in but the sales rep ID might be null. ...
Selecting empty text input using jQuery
How do I identify empty textboxes using jQuery? I would like to do it using selectors if it is at all possible. Also, I must select on id since in the real code where I want to use this I don't want to select all text inputs.
...
Preventing Laravel adding multiple records to a pivot table
...condition like this one :
if (! $cart->items->contains($newItem->id)) {
$cart->items()->save($newItem);
}
Or/and you can add unicity condition in your database, it would throw an exception during an attempt of saving a doublet.
You should also take a look at the more straightf...
How can I remove or replace SVG content?
... the solution:
d3.select("svg").remove();
This is a remove function provided by D3.js.
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SQL Server indexes - ascending or descending, what difference does it make?
...y Optimiser's point of view.
For the table definition
CREATE TABLE T1( [ID] [int] IDENTITY NOT NULL,
[Filler] [char](8000) NULL,
PRIMARY KEY CLUSTERED ([ID] ASC))
The Query
SELECT TOP 10 *
FROM T1
ORDER BY ID DESC
Uses an ordered scan with scan direction BAC...
MySQL Multiple Joins in one query?
... dashboard_data.headline, dashboard_data.message, dashboard_messages.image_id, images.filename
FROM dashboard_data
INNER JOIN dashboard_messages
ON dashboard_message_id = dashboard_messages.id
INNER JOIN images
ON dashboard_messages.image_id = images.image_id
However be ...
When to use EntityManager.find() vs EntityManager.getReference() with JPA
...ormal) where I use the EntityManager.getReference(LObj.getClass(), LObj.getId()) to get a database entity and then pass the returned object to be persisted in another table.
...
Rest with Express.js nested router
...
You can nest routers by attaching them as middleware on an other router, with or without params.
You must pass {mergeParams: true} to the child router if you want to access the params from the parent router.
mergeParams was introduced in Express 4.5.0 (Jul 5 2014)...
How to count occurrences of a column value efficiently in SQL?
...
SELECT age, count(age)
FROM Students
GROUP by age
If you need the id as well you could include the above as a sub query like so:
SELECT S.id, S.age, C.cnt
FROM Students S
INNER JOIN (SELECT age, count(age) as cnt
FROM Students
GROUP BY ag...
How to transfer some data to another Fragment?
...lass implements Serializable {
private static final long serialVersionUID = -2163051469151804394L;
private int id;
private String created;
}
In you FromFragment:
Bundle args = new Bundle();
args.putSerializable(TAG_MY_CLASS, myClass);
Fragment toFragment = new ToFragment();
toFragment...