system/Database/MySQLi/Connection.php
protected function prepQuery(string $sql): string
	{
		// mysqli_affected_rows() returns 0 for "DELETE FROM TABLE" queries. This hack
		// modifies the query so that it a proper number of affected rows is returned.
		if ($this->deleteHack === true && preg_match('/^\s*DELETE\s+FROM\s+(\S+)\s*$/i', $sql))
		{
			return trim($sql) . ' WHERE 1=1';
		}

		return $sql;
	}
protected function prepQuery(string $sql): string
	{
		// mysqli_affected_rows() returns 0 for "DELETE FROM TABLE" queries. This hack
		// modifies the query so that it a proper number of affected rows is returned.
		if ($this->deleteHack === true && preg_match('/^\s*DELETE\s+FROM\s+(\S+)\s*$/i', $sql))
		{
			return trim($sql) . ' WHERE 1=1';
		}

		return $sql;
	}
Prep the query

If needed, each database adapter can prep the query string

@param string $sql an SQL query

@return string