Thank you in advance
You do not write an update SQL you use the applyEdits method on a FeatureLayer class.
https://developers.arcgis.com/javascript/3/jsapi/featurelayer-amd.html#applyedits
It will very helpful if you tell me how should i integrate featureLayer class with webscene and sceneview in a code ? because i am unable to do so in a code
ScreneView is just a 3D map so the map contains layers you need to access the layer in the scenview and if that layer is from a FeatureServer service then it has the ability to applyUpdates if it is from a MapServer service then you can not apply edits. So it all depends on how your scene view is created. Is it created by adding layers in the code or by as webmap id?