Record the problems encountered in learning: Borrowing from the ArcGIS API, querying by attributes, filtering by conditions, you should pay attention to the type of fields, otherwise it is easy to not know where the mistake is, especially if the front end is used to it. For example, filtering corresponding to integer type fields:
layer.definitionExpression = "FID=" + ID
When filtering properties of string type, attention should be paid to string symbols:
layer.definitionExpression="indexID='"+ID+"'"
In short, he was careless and did not pay attention to the query logic.