columns:id|TEXT	minimum_board_thickness|NUMERIC	board_thickness|NUMERIC	vertical_drilling_diameter|NUMERIC	span|NUMERIC	double_headed|NUMERIC	connector_distance|NUMERIC	vertical_drilling_depth|NUMERIC	horizontal_drilling_diameter|NUMERIC	horizontal_drilling_depth|NUMERIC	series_bolt|TEXT	head_diameter|NUMERIC	former_id|TEXT	symbol_name|TEXT	symbol_name2|TEXT	angle_max|NUMERIC	twin_dowel|NUMERIC	socket_add|NUMERIC
indexes:id|UNIQUE
