function views_join::build_join

Build the SQL for the join this object represents.

When possible, try to use table alias instead of table names.

Parameters

$select_query: An implementation of SelectQueryInterface.

$table: The base table to join.

$view_query: The source query, implementation of views_plugin_query.

File

modules/views/includes/handlers.inc, line 1047

Defines the various handler objects to help build and display views.

Class

views_join

A function class to represent a join and create the SQL necessary to implement the join.

Code

function build_join($select_query, $table, $view_query) {
  if (empty($this->definition['table formula'])) {
    $right_table = $this->table;
  }
  else {
    $right_table = $this->definition['table formula'];
  }

  if ($this->left_table) {
    $left = $view_query->get_table_info($this->left_table);
    $left_field = "$left[alias].$this->left_field";
  }
  else {
    // This can be used if left_field is a formula or something. It should be
    // used only *very* rarely.
    $left_field = $this->left_field;
  }

  $condition = "$left_field = $table[alias].$this->field";
  $arguments = array();

  // Tack on the extra.
  if (isset($this->extra)) {
    // If extra has been provided as string instead of an array, convert it
    // to an array.
    if (!is_array($this->extra)) {
      $this->extra = array($this->extra);
    }

    $extras = array();
    foreach ($this->extra as $info) {
      if (is_array($info)) {
        $extra = '';
        // Figure out the table name. Remember, only use aliases provided if
        // at all possible.
        $join_table = '';
        if (!array_key_exists('table', $info)) {
          $join_table = $table['alias'] . '.';
        }
        elseif (isset($info['table'])) {
          // If we're aware of a table alias for this table, use the table
          // alias instead of the table name.
          if (isset($left) && $left['table'] == $info['table']) {
            $join_table = $left['alias'] . '.';
          }
          else {
            $join_table = $info['table'] . '.';
          }
        }

        // Convert a single-valued array of values to the single-value case,
        // and transform from IN() notation to = notation.
        if (is_array($info['value']) && count($info['value']) == 1) {
          if (empty($info['operator'])) {
            $operator = '=';
          }
          else {
            $operator = $info['operator'] == 'NOT IN' ? '!=' : '=';
          }
          $info['value'] = array_shift($info['value']);
        }

        if (is_array($info['value'])) {
          $value_placeholders = array();

          // With an array of values, we need multiple placeholders and the
          // 'IN' operator is implicit.
          foreach ($info['value'] as $value) {
            $placeholder_i = $view_query->placeholder('views_join_condition_');
            $value_placeholders[] = $placeholder_i;
            $arguments[$placeholder_i] = $value;
          }

          $operator = !empty($info['operator']) ? $info['operator'] : 'IN';
          $placeholder = '( ' . implode(', ', $value_placeholders) . ' )';
        }
        else {
          // With a single value, the '=' operator is implicit.
          $operator = !empty($info['operator']) ? $info['operator'] : '=';
          $placeholder = $view_query->placeholder('views_join_condition_');
          $arguments[$placeholder] = $info['value'];
        }
        $extras[] = "$join_table$info[field] $operator $placeholder";
      }
      elseif (is_string($info)) {
        $extras[] = $info;
      }
    }

    if ($extras) {
      if (count($extras) == 1) {
        $condition .= ' AND (' . array_shift($extras) . ')';
      }
      else {
        $condition .= ' AND (' . implode(' ' . $this->extra_type . ' ', $extras) . ')';
      }
    }
  }

  $select_query->addJoin($this->type, $right_table, $table['alias'], $condition, $arguments);
}