function Schema::addField

File

core/modules/sqlite/src/Driver/Database/sqlite/Schema.php, line 319

Class

Schema

SQLite implementation of \Drupal\Core\Database\Schema.

Namespace

Code

public function addField($table, $field, $specification, $keys_new = []) {
  if (!$this->tableExists($table)) {
    throw new SchemaObjectDoesNotExistException("Cannot add field '{$table}.{$field}': table doesn't exist.");
  }
  if ($this->fieldExists($table, $field)) {
    throw new SchemaObjectExistsException("Cannot add field '{$table}.{$field}': field already exists.");
  }
  if (isset($keys_new['primary key']) && in_array($field, $keys_new['primary key'], TRUE)) {
    $this->ensureNotNullPrimaryKey($keys_new['primary key'], [
      $field => $specification,
    ]);
  }
  // SQLite doesn't have a full-featured ALTER TABLE statement. It only
  // supports adding new fields to a table, in some simple cases. In most
  // cases, we have to create a new table and copy the data over.
  if (empty($keys_new) && (empty($specification['not null']) || isset($specification['default']))) {
    // When we don't have to create new keys and we are not creating a
    // NOT NULL column without a default value, we can use the quicker version.
    $query = 'ALTER TABLE {' . $table . '} ADD ' . $this->createFieldSql($field, $this->processField($specification));
    $this->connection
      ->query($query);
    // Apply the initial value if set.
    if (isset($specification['initial_from_field'])) {
      if (isset($specification['initial'])) {
        $expression = 'COALESCE(' . $specification['initial_from_field'] . ', :default_initial_value)';
        $arguments = [
          ':default_initial_value' => $specification['initial'],
        ];
      }
      else {
        $expression = $specification['initial_from_field'];
        $arguments = [];
      }
      $this->connection
        ->update($table)
        ->expression($field, $expression, $arguments)
        ->execute();
    }
    elseif (isset($specification['initial'])) {
      $this->connection
        ->update($table)
        ->fields([
        $field => $specification['initial'],
      ])
        ->execute();
    }
  }
  else {
    // We cannot add the field directly. Use the slower table alteration
    // method, starting from the old schema.
    $old_schema = $this->introspectSchema($table);
    $new_schema = $old_schema;
    // Add the new field.
    $new_schema['fields'][$field] = $specification;
    // Build the mapping between the old fields and the new fields.
    $mapping = [];
    if (isset($specification['initial_from_field'])) {
      // If we have an initial value, copy it over.
      if (isset($specification['initial'])) {
        $expression = 'COALESCE(' . $specification['initial_from_field'] . ', :default_initial_value)';
        $arguments = [
          ':default_initial_value' => $specification['initial'],
        ];
      }
      else {
        $expression = $specification['initial_from_field'];
        $arguments = [];
      }
      $mapping[$field] = [
        'expression' => $expression,
        'arguments' => $arguments,
      ];
    }
    elseif (isset($specification['initial'])) {
      // If we have an initial value, copy it over.
      $mapping[$field] = [
        'expression' => ':newfieldinitial',
        'arguments' => [
          ':newfieldinitial' => $specification['initial'],
        ],
      ];
    }
    else {
      // Else use the default of the field.
      $mapping[$field] = NULL;
    }
    // Add the new indexes.
    $new_schema = array_merge($new_schema, $keys_new);
    $this->alterTable($table, $old_schema, $new_schema, $mapping);
  }
}