Schema::queryFieldInformation

public Schema::queryFieldInformation($table, $field)

public function queryFieldInformation($table, $field) {
  $prefixInfo = $this->getPrefixInfo($table, TRUE);

  // Split the key into schema and table for querying.
  $schema = $prefixInfo['schema'];
  $table_name = $prefixInfo['table'];

  $this->connection->addSavepoint();

  try {
    $checks = $this->connection->query("SELECT conname FROM pg_class cl INNER JOIN pg_constraint co ON co.conrelid = cl.oid INNER JOIN pg_attribute attr ON attr.attrelid = cl.oid AND attr.attnum = ANY (co.conkey) INNER JOIN pg_namespace ns ON cl.relnamespace = ns.oid WHERE co.contype = 'c' AND ns.nspname = :schema AND cl.relname = :table AND attr.attname = :column", array(
      ':schema' => $schema,
      ':table' => $table_name,
      ':column' => $field,
    ));
  }
  catch (\Exception $e) {
    $this->connection->rollbackSavepoint();
    throw $e;
  }

  $this->connection->releaseSavepoint();

  $field_information = $checks->fetchCol();

  return $field_information;
}