public function BaseFieldDefinition::getSchema

Returns the field schema.

Note that this method returns an empty array for computed fields which have no schema.

Return value

array[] The field schema, as an array of key/value pairs in the format returned by \Drupal\Core\Field\FieldItemInterface::schema():

• columns: An array of Schema API column specifications, keyed by column name. This specifies what comprises a single value for a given field. No assumptions should be made on how storage backends internally use the original column name to structure their storage.
• indexes: An array of Schema API index definitions. Some storage backends might not support indexes.
• unique keys: An array of Schema API unique key definitions. Some storage backends might not support unique keys.
• foreign keys: An array of Schema API foreign key definitions. Note, however, that depending on the storage backend specified for the field, the field data is not necessarily stored in SQL.

Overrides FieldStorageDefinitionInterface::getSchema

File

core/lib/Drupal/Core/Field/BaseFieldDefinition.php, line 663

Class

BaseFieldDefinition

A class for defining entity fields.

Namespace

Code

public function getSchema() {
  if (!isset($this->schema)) {

    // Get the schema from the field item class.
    $definition = \Drupal::service('plugin.manager.field.field_type')
      ->getDefinition($this
      ->getType());
    $class = $definition['class'];
    $schema = $class::schema($this);

    // Fill in default values.
    $schema += [
      'columns' => [],
      'unique keys' => [],
      'indexes' => [],
      'foreign keys' => [],
    ];

    // Merge custom indexes with those specified by the field type. Custom
    // indexes prevail.
    $schema['indexes'] = $this->indexes + $schema['indexes'];
    $this->schema = $schema;
  }
  return $this->schema;
}