@Override
 protected void accept0(SQLASTVisitor visitor) {
   if (visitor.visit(this)) {
     acceptChild(visitor, union);
   }
   visitor.endVisit(this);
 }
 protected void accept0(SQLASTVisitor visitor) {
   if (visitor.visit(this)) {
     acceptChild(visitor, name);
     acceptChild(visitor, on);
     acceptChild(visitor, body);
   }
   visitor.endVisit(this);
 }
 @Override
 protected void accept0(SQLASTVisitor visitor) {
   if (visitor.visit(this)) {
     acceptChild(visitor, this.selectList);
     acceptChild(visitor, this.from);
     acceptChild(visitor, this.where);
     acceptChild(visitor, this.groupBy);
   }
   visitor.endVisit(this);
 }
 @Override
 protected void accept0(SQLASTVisitor visitor) {
   if (visitor.visit(this)) {
     this.acceptChild(visitor, name);
     this.acceptChild(visitor, dataType);
     this.acceptChild(visitor, defaultExpr);
     this.acceptChild(visitor, constraints);
   }
   visitor.endVisit(this);
 }