Consistency in error handling (fb-1799) (FeatureBaseDB#2383)

* return 200 once plan compilation starts; if error, return error in response.

* removed some commented out code that is definitely not needed.

(cherry picked from commit 9dda3ff)

Author: paddyjok

http_handler.go

@@ -1420,13 +1420,6 @@ func (h *Handler) handlePostSQL(w http.ResponseWriter, r *http.Request) {
 	// put the requestId in the context
 	ctx := fbcontext.WithRequestID(r.Context(), requestID.String())
 
-	sql := string(b)
-	rootOperator, err := h.api.CompilePlan(ctx, sql)
-	if err != nil {
-		h.writeBadRequest(w, r, err)
-		return
-	}
-
 	// Write response back to client.
 	w.Header().Set("Content-Type", "application/json")
 
@@ -1501,6 +1494,13 @@ func (h *Handler) handlePostSQL(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
+	sql := string(b)
+	rootOperator, err := h.api.CompilePlan(ctx, sql)
+	if err != nil {
+		writeError(err, false)
+		return
+	}
+
 	// Get a query iterator.
 	iter, err := rootOperator.Iterator(ctx, nil)
 	if err != nil {

sql3/parser/walk.go

@@ -165,9 +165,6 @@ func walk(v Visitor, node Node) (_ Node, err error) {
 		if err := walkIdent(v, &n.Name); err != nil {
 			return node, err
 		}
-		// if err := walkIdentList(v, n.UpdateOfColumns); err != nil {
-		// 	return node, err
-		// }
 		for i := range n.Body {
 			if body, err := walk(v, n.Body[i]); err != nil {
 				return node, err
@@ -188,15 +185,6 @@ func walk(v Visitor, node Node) (_ Node, err error) {
 				n.WithClause = nil
 			}
 		}
-		/*for i := range n.ValueLists {
-			if list, err := walk(v, n.ValueLists[i]); err != nil {
-				return node, err
-			} else if list != nil {
-				n.ValueLists[i] = list.(*ExprList)
-			} else {
-				n.ValueLists[i] = nil
-			}
-		}*/
 		for i := range n.Columns {
 			if col, err := walk(v, n.Columns[i]); err != nil {
 				return node, err
@@ -289,15 +277,6 @@ func walk(v Visitor, node Node) (_ Node, err error) {
 				n.Select = nil
 			}
 		}*/
-		/*if n.UpsertClause != nil {
-			if clause, err := walk(v, n.UpsertClause); err != nil {
-				return node, err
-			} else if clause != nil {
-				n.UpsertClause = clause.(*UpsertClause)
-			} else {
-				n.UpsertClause = nil
-			}
-		}*/
 
 	case *UpdateStatement:
 		if n.WithClause != nil {
@@ -373,21 +352,6 @@ func walk(v Visitor, node Node) (_ Node, err error) {
 		if err := walkExpr(v, &n.WhereExpr); err != nil {
 			return node, err
 		}
-		// for i := range n.OrderingTerms {
-		// 	if term, err := walk(v, n.OrderingTerms[i]); err != nil {
-		// 		return node, err
-		// 	} else if term != nil {
-		// 		n.OrderingTerms[i] = term.(*OrderingTerm)
-		// 	} else {
-		// 		n.OrderingTerms[i] = nil
-		// 	}
-		// }
-		// if err := walkExpr(v, &n.LimitExpr); err != nil {
-		// 	return node, err
-		// }
-		// if err := walkExpr(v, &n.OffsetExpr); err != nil {
-		// 	return node, err
-		// }
 
 	case *PrimaryKeyConstraint:
 		if err := walkIdent(v, &n.Name); err != nil {