UPDATE unit_gearbox_structure gearbox_code = #{item.gearboxCode}, gearbox_code = null, gearbox_structure = #{item.gearboxStructure}, gearbox_structure = null, planetary_gear_grade = #{item.planetaryGearGrade}, planetary_gear_grade = null, large_gear_teeth_count = #{item.largeGearTeethCount}, large_gear_teeth_count = null, small_gear_teeth_count = #{item.smallGearTeethCount}, small_gear_teeth_count = null, bearing_brand = #{item.bearingBrand}, bearing_brand = null, bearing_model = #{item.bearingModel}, bearing_model = null, gear_ring_teeth_count = #{item.gearRingTeethCount}, gear_ring_teeth_count = null, sun_wheel_teeth_count = #{item.sunWheelTeethCount}, sun_wheel_teeth_count = null, planet_wheel_count = #{item.planetWheelCount}, planet_wheel_count = null, planet_wheel_teeth_count = #{item.planetWheelTeethCount}, planet_wheel_teeth_count = null, sun_wheel_bearing_brand =#{item.sunWheelBearingBrand}, sun_wheel_bearing_brand = null, sun_wheel_bearing_model =#{item.sunWheelBearingModel}, sun_wheel_bearing_model = null, update_by = #{item.updateBy}, update_by = = null, update_time = #{item.updateTime} update_time = null WHERE id = #{item.id}