private function DatabaseConnection_mysql::quoteIdentifier

Quotes an identifier with backticks for MySQL 8 compatibility.

Not all identifiers need quotes, only keywords, but we add them on all fields and table names for consistency and to ease compatibility in the future.

Parameters

string $identifier: The field to check.

Return value

string: The identifier, quoted with backticks.

File

core/includes/database/mysql/database.inc, line 168

Database interface code for MySQL database servers.

Class

DatabaseConnection_mysql

Code

private function quoteIdentifier($identifier) {
  // Some identifiers are empty, such as when doing expressions.
  if (strlen($identifier) === 0) {
    return $identifier;
  }
  // Identifiers that have both a table and field should quote both.
  elseif (strpos($identifier, '.') !== FALSE) {
    list($table, $identifier) = explode('.', $identifier, 2);
    return "`$table`" . '.' . "`$identifier`";
  }
  // Otherwise quote just the field name.
  return "`$identifier`";
}