function Sql::add_field in Views (for Drupal 7) 8.3

Add a field to the query table, possibly with an alias. This will automatically call ensure_table to make sure the required table exists, *unless* $table is unset.

Parameters

$table: The table this field is attached to. If NULL, it is assumed this will be a formula; otherwise, ensure_table is used to make sure the table exists.

$field: The name of the field to add. This may be a real field or a formula.

$alias: The alias to create. If not specified, the alias will be $table_$field unless $table is NULL. When adding formulae, it is recommended that an alias be used.

$params: An array of parameters additional to the field that will control items such as aggregation functions and DISTINCT.

Return value

$name The name that this field can be referred to as. Usually this is the alias.

2 calls to Sql::add_field()

Sql::add_orderby in lib/Drupal/views/Plugin/views/query/Sql.php

Add an ORDER BY clause to the query.

Sql::query in lib/Drupal/views/Plugin/views/query/Sql.php

Generate a query and a countquery from all of the information supplied to the object.

File

lib/Drupal/views/Plugin/views/query/Sql.php, line 743

Definition of Drupal\views\Plugin\views\query\Sql.

Class

Sql

@todo.

Namespace

Drupal\views\Plugin\views\query

Code

function add_field($table, $field, $alias = '', $params = array()) {

  // We check for this specifically because it gets a special alias.
  if ($table == $this->base_table && $field == $this->base_field && empty($alias)) {
    $alias = $this->base_field;
  }
  if ($table && empty($this->table_queue[$table])) {
    $this
      ->ensure_table($table);
  }
  if (!$alias && $table) {
    $alias = $table . '_' . $field;
  }

  // Make sure an alias is assigned
  $alias = $alias ? $alias : $field;

  // PostgreSQL truncates aliases to 63 characters: http://drupal.org/node/571548
  // We limit the length of the original alias up to 60 characters
  // to get a unique alias later if its have duplicates
  $alias = strtolower(substr($alias, 0, 60));

  // Create a field info array.
  $field_info = array(
    'field' => $field,
    'table' => $table,
    'alias' => $alias,
  ) + $params;

  // Test to see if the field is actually the same or not. Due to
  // differing parameters changing the aggregation function, we need
  // to do some automatic alias collision detection:
  $base = $alias;
  $counter = 0;
  while (!empty($this->fields[$alias]) && $this->fields[$alias] != $field_info) {
    $field_info['alias'] = $alias = $base . '_' . ++$counter;
  }
  if (empty($this->fields[$alias])) {
    $this->fields[$alias] = $field_info;
  }

  // Keep track of all aliases used.
  $this->field_aliases[$table][$field] = $alias;
  return $alias;
}