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SQL join: selecting the last records in a one-to-many relationship
...omer. I want to get a list of all customers along with their last purchase in one SELECT statement. What is the best practice? Any advice on building indexes?
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Rails find record with zero has_many records associated [duplicate]
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Bah, found it here: https://stackoverflow.com/a/5570221/417872
City.includes(:photos).where(photos: { city_id: nil })
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Remove by _id in MongoDB console
In the MongoDB console how can I remove a record by id? Here's my collection :
11 Answers
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Start an Activity with a parameter
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Put an int which is your id into the new Intent.
Intent intent = new Intent(FirstActivity.this, SecondActivity.class);
Bundle b = new Bundle();
b.putInt("key", 1); //Your id
intent.putExtras(b); //Put your id to your next Intent
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how to add records to has_many :through association in rails
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I think you can simply do this:
@cust = Customer.new(params[:customer])
@cust.houses << House.find(params[:house_id])
Or when creating a new house for a customer:
@cust = Customer.new(params[:customer])
@cust.houses...
Want to find records with no associated records in Rails
...s is still pretty close to SQL, but it should get everyone with no friends in the first case:
Person.where('id NOT IN (SELECT DISTINCT(person_id) FROM friends)')
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Android custom dropdown/popup menu
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Update: To create a popup menu in android with Kotlin refer my answer here.
To create a popup menu in android with Java:
Create a layout file activity_main.xml under res/layout directory which contains only one button.
Filename: activity_main.xml
<R...
Get the Last Inserted Id Using Laravel Eloquent
I'm currently using the below code to insert data in a table:
32 Answers
32
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Can table columns with a Foreign Key be NULL?
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Yes, you can enforce the constraint only when the value is not NULL. This can be easily tested with the following example:
CREATE DATABASE t;
USE t;
CREATE TABLE parent (id INT NOT NULL,
PRIMARY KEY (id)
) ENGINE=INNODB;
CREATE TABLE...
Add new item count to icon on button - Android
...have functional app but wonder how to even approach this? Particulary, I'm interested in how to show Number of "New" items under tabs. What I KNOW how to do - is create new icons with red dots and just display them when new stuff available.
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