public boolean visit(SQLJoinTableSource x) {
   x.getLeft().accept(this);
   x.getRight().accept(this);
   if (x.getCondition() != null) {
     x.getCondition().accept(this);
   }
   return false;
 }
  public void test_leftJoin() throws Exception {
    String sql =
        "SELECT host.id as id" //
            + ",   host.item_id as itemId" //
            + ",   host.node_id as nodeId" //
            + ",   host.node_type as nodeType" //
            + ",   host.begin_time as beginTime" //
            + ",   host.end_time as endTime" //
            + ",   host.gmt_create as gmtCreate" //
            + ",   host.gmt_modify as gmtModify" //
            + ",   host.reason as reason" //
            + ",   host.creator_id as creatorId" //
            + ",   host.modifier_id as modifierId" //
            + ",   user.name as creator" //
            + ",   user.name as modifier" //
            + ",   user.nick_name as nickName   " //
            + " FROM notice_close_node host left join sys_user user on user.id = host.modifier_id";

    TeradataStatementParser parser = new TeradataStatementParser(sql);
    List<SQLStatement> statementList = parser.parseStatementList();
    SQLStatement statemen = statementList.get(0);
    print(statementList);

    Assert.assertEquals(1, statementList.size());

    {
      SQLSelectStatement selectStmt = (SQLSelectStatement) statemen;
      SQLSelect selectSQL = selectStmt.getSelect();
      TeradataSelectQueryBlock queryBlock = (TeradataSelectQueryBlock) selectSQL.getQuery();

      Assert.assertTrue(queryBlock.getFrom() instanceof SQLJoinTableSource);

      SQLJoinTableSource joinSource = (SQLJoinTableSource) queryBlock.getFrom();

      Assert.assertEquals(joinSource.getJoinType().toString(), "LEFT_OUTER_JOIN");
      Assert.assertEquals(joinSource.getLeft().toString(), "notice_close_node");
      Assert.assertEquals(joinSource.getRight().toString(), "sys_user");
      Assert.assertNotNull(joinSource.getCondition());
    }

    TeradataSchemaStatVisitor visitor = new TeradataSchemaStatVisitor();
    statemen.accept(visitor);

    System.out.println("Tables : " + visitor.getTables());
    System.out.println("fields : " + visitor.getColumns());
    System.out.println("coditions : " + visitor.getConditions());
    System.out.println("orderBy : " + visitor.getOrderByColumns());

    Assert.assertEquals(2, visitor.getTables().size());
    Assert.assertEquals(15, visitor.getColumns().size());
    Assert.assertEquals(2, visitor.getConditions().size());

    Assert.assertTrue(visitor.getColumns().contains(new Column("sys_user", "id")));
    Assert.assertTrue(
        visitor.getColumns().contains(new Column("notice_close_node", "modifier_id")));
    System.out.println(
        "------ end of " + new Object() {}.getClass().getEnclosingMethod().getName() + " ------");
  }
  private void setColumn(SQLExpr x, Column column) {
    SQLObject current = x;
    for (; ; ) {
      SQLObject parent = current.getParent();

      if (parent == null) {
        break;
      }

      if (parent instanceof SQLSelectQueryBlock) {
        SQLSelectQueryBlock query = (SQLSelectQueryBlock) parent;
        if (query.getWhere() == current) {
          column.setWhere(true);
        }
        break;
      }

      if (parent instanceof SQLSelectGroupByClause) {
        SQLSelectGroupByClause groupBy = (SQLSelectGroupByClause) parent;
        if (current == groupBy.getHaving()) {
          column.setHaving(true);
        } else if (groupBy.getItems().contains(current)) {
          column.setGroupBy(true);
        }
        break;
      }

      if (parent instanceof SQLSelectItem) {
        column.setSelec(true);
        break;
      }

      if (parent instanceof SQLJoinTableSource) {
        SQLJoinTableSource join = (SQLJoinTableSource) parent;
        if (join.getCondition() == current) {
          column.setJoin(true);
        }
        break;
      }

      current = parent;
    }
  }
  public void test_crossJoin() throws Exception {
    String sql = "SELECT * FROM t1 CROSS JOIN t2 ON t1.id = t2.id;";

    TeradataStatementParser parser = new TeradataStatementParser(sql);
    List<SQLStatement> statementList = parser.parseStatementList();
    SQLStatement statement = statementList.get(0);
    print(statementList);

    Assert.assertEquals(1, statementList.size());
    {
      SQLSelectStatement selectStmt = (SQLSelectStatement) statement;
      SQLSelect selectSQL = selectStmt.getSelect();
      TeradataSelectQueryBlock queryBlock = (TeradataSelectQueryBlock) selectSQL.getQuery();

      Assert.assertTrue(queryBlock.getFrom() instanceof SQLJoinTableSource);

      SQLJoinTableSource joinSource = (SQLJoinTableSource) queryBlock.getFrom();

      Assert.assertEquals(joinSource.getJoinType().toString(), "CROSS_JOIN");
      Assert.assertEquals(joinSource.getLeft().toString(), "t1");
      Assert.assertEquals(joinSource.getRight().toString(), "t2");
      Assert.assertNotNull(joinSource.getCondition());
    }

    TeradataSchemaStatVisitor visitor = new TeradataSchemaStatVisitor();
    statement.accept(visitor);

    System.out.println("Tables : " + visitor.getTables());
    System.out.println("fields : " + visitor.getColumns());
    System.out.println("coditions : " + visitor.getConditions());
    System.out.println("orderBy : " + visitor.getOrderByColumns());

    Assert.assertEquals(2, visitor.getTables().size());
    System.out.println(
        "------ end of " + new Object() {}.getClass().getEnclosingMethod().getName() + " ------");
  }