improve sqlwall

src/main/java/com/alibaba/druid/sql/ast/SQLOrderBy.java

@@ -35,6 +35,13 @@ public class SQLOrderBy extends SQLObjectImpl {
         this.items.add(item);
     }
 
+    public void addItem(SQLSelectOrderByItem item) {
+        if (item != null) {
+            item.setParent(this);
+        }
+        this.items.add(item);
+    }
+
     public List<SQLSelectOrderByItem> getItems() {
         return this.items;
     }

src/main/java/com/alibaba/druid/sql/ast/statement/SQLSelectGroupByClause.java

@@ -51,4 +51,11 @@ public class SQLSelectGroupByClause extends SQLObjectImpl {
     public List<SQLExpr> getItems() {
         return this.items;
     }
+
+    public void addItem(SQLExpr sqlExpr) {
+        if (sqlExpr != null) {
+            sqlExpr.setParent(this);
+            this.items.add(sqlExpr);
+        }
+    }
 }