whereClause

A SQL expression that defines the dynamic entities to return. Use this property to filter dynamic entities by attribute value. Setting this property forces the server to filter observations using the given expression before adding them to the stream.

The expression used as the ArcGISStreamServiceFilter.whereClause should follow standard SQL syntax as discussed in the document https://pro.arcgis.com/en/pro-app/latest/help/mapping/navigation/sql-reference-for-elements-used-in-query-expressions.htm.

The default value is an empty string, meaning that no attribute filter will be applied to the stream.