Preserve the TryCast expression in columnize_expr (#4574)

Author: jonahgao

datafusion/expr/src/utils.rs

@@ -688,6 +688,10 @@ pub fn columnize_expr(e: Expr, input_schema: &DFSchema) -> Expr {
             expr: Box::new(columnize_expr(*expr, input_schema)),
             data_type,
         }),
+        Expr::TryCast { expr, data_type } => Expr::TryCast {
+            expr: Box::new(columnize_expr(*expr, input_schema)),
+            data_type,
+        },
         Expr::ScalarSubquery(_) => e.clone(),
         _ => match e.display_name() {
             Ok(name) => match input_schema.field_with_unqualified_name(&name) {

datafusion/sql/src/planner.rs

@@ -3394,6 +3394,16 @@ mod tests {
         );
     }
 
+    #[test]
+    fn try_cast_from_aggregation() {
+        quick_test(
+            "SELECT TRY_CAST(SUM(age) AS FLOAT) FROM person",
+            "Projection: TRY_CAST(SUM(person.age) AS Float32)\
+            \n  Aggregate: groupBy=[[]], aggr=[[SUM(person.age)]]\
+            \n    TableScan: person",
+        );
+    }
+
     #[test]
     fn cast_to_invalid_decimal_type() {
         // precision == 0