qgis字段计算器

CASE WHEN "class" = 10.0 THEN 0.05 WHEN "class" = 20.0 THEN 0.06 WHEN "class" = 30.0 THEN 0.05 WHEN "class" = 40.0 THEN 0.035 WHEN "class" = 50.0 THEN 0.1 WHEN "class" = 60.0 THEN 0.03 WHEN "class" = 70.0 THEN 0.025 WHEN "class" = 80.0 THEN 0.03 WHEN "class" = 90.0 THEN 0.03 WHEN "class" = 95.0 THEN 0.04 WHEN "class" = 100 THEN 0.03 END