Distinct

This cheat sheet provides an overview of commonly used methods, classes, and interfaces for content entities.

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Content entities inherit much of their behavior from entities. See Working with the Entity API for these shared features.

Managing Field Values

Create custom fields using the baseFieldDefinitions method for your content entity.

• Load a custom entity instance into a local variable $Custom_Entity
• Define a custom field named "custom_field"
• Store some data

Code Example

$custom_field_value = $Custom_Entity->custom_field->value;
// Perform some kind of data manipulation
$Custom_Entity->custom_field->value = $custom_field_value;
$Custom_Entity->save();

Example content entities:

• node
• comment
• user

Configuration entities use the Entity API to store configuration in the database.

Differences from Content Entities

• Integrates with the CMI API for export capabilities
• No fields
• Uses schema file (Content Entities use hook_schema())

Tutorials

• Drupal example: Creating a configuration entity type in Drupal 8
• Change record: https://www.drupal.org/node/1818734

In Drupal 8, bundles are a type of container for information that holds field definitions or settings. They are sometimes referred to as "subtypes." Bundles are optional and sit below entity types in the hierarchy of information containers.

• Entity variants (content and configuration; many entities are paired, e.g., blocks)

- Entity Types
- Bundles or subtypes (optional)

Examples of these container types:

• Entity variants:

1) Content
Content entity types:
1. Node:
- Node bundles, also known as content types:
* Article
* Basic Page

2. Taxonomy
- Taxonomy bundles, also known as vocabularies:

* <Vocabulary A>
* <Vocabulary B>
* <Vocabulary Etc.>

3. Blocks
- Custom Block Bundles, also known as Block Types:

* <Block Type L>
* <Block Type M>
* <Block Type Etc.>

4. User (no child bundles)
5. <Custom content entity type X>
6. <Custom content entity type Y>
7. <Custom content entity type Etc.>

2) Configuration
Configuration entity types:
* Custom Block types (no child bundles)
* View (no child bundles)
* Menu (no child bundles)
* Role (no child bundles)
* <Custom config entity type I>
* <Custom config entity type II>
* <Custom config entity type Etc.>

Distinct Queries

Some SQL queries can yield duplicate results. In such cases, duplicate rows can be filtered using the "DISTINCT" keyword in a static query. In a dynamic query, use the distinct() method.

// Force filtering of duplicate records in the result set.
$connection = \Drupal::database();
$query = $connection->select('my_table', 'mt');
$query->fields('mt', ['my_fields']);
$query->distinct()->execute()->fetchAll();

Note that DISTINCT can impact performance, so it should only be used when necessary to avoid duplicates.