improve sqlwall rule

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

@@ -50,6 +50,9 @@ public class SQLCreateTableStatement extends SQLStatementImpl implements SQLDDLS
     }
 
     public void setTableSource(SQLExprTableSource tableSource) {
+        if (tableSource != null) {
+            tableSource.setParent(this);
+        }
         this.tableSource = tableSource;
     }
 

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

@@ -16,7 +16,8 @@
 package com.alibaba.druid.sql.ast.statement;
 
 public enum SQLUnionOperator {
-    UNION("UNION"), UNION_ALL("UNION ALL"), MINUS("MINUS"), INTERSECT("INTERSECT"), DISTINCT("UNION DISTINCT");
+    UNION("UNION"), UNION_ALL("UNION ALL"), MINUS("MINUS"), EXCEPT("EXCEPT"), INTERSECT("INTERSECT"),
+    DISTINCT("UNION DISTINCT");
 
     public final String name;