Java 列出已解析的SQL SELECT语句的所有表/列

我试图使用JSqlParser从SQL SELECT语句中提取表/列列表。选择包含计算和嵌套选择：

SELECT col1 AS a, (col2 - col21) AS b, col3 AS c FROM table1 
       where col1 in (select col4 from table4)

这应返回：

col1 table1
col2 table1
col21 table1
col3 table1
col4 table4

如果我用

CCJSqlParserUtil

解析它，我会得到不同的结果：

    Select stmt = (Select) CCJSqlParserUtil.parse("SELECT col1 AS a, col2 AS b, col3 AS c "
            + "FROM table1 WHERE where col1 in (select col4 from table4)");
    Map<String, Expression> map = new HashMap<>();        
    for (SelectItem selectItem : ((PlainSelect)stmt.getSelectBody()).getSelectItems()) {
        selectItem.accept(new SelectItemVisitorAdapter() {
            @Override
            public void visit(SelectExpressionItem item) {
                map.put(item.getAlias().getName(), item.getExpression());
            }
        });
    }

    System.out.println("map " + map); 

这不是我想要的。SELECT语句甚至可能更复杂，包括嵌套和子嵌套SELECT；有没有办法获取所有列/表的列表？

要提取所有表名（模拟列名），您可以使用TableNamesFinder：

Statement statement = CCJSqlParserUtil.parse("SELECT * FROM MY_TABLE1");
Select selectStatement = (Select) statement;
TablesNamesFinder tablesNamesFinder = new TablesNamesFinder();
List<String> tableList = tablesNamesFinder.getTableList(selectStatement);

Statement statement = CCJSqlParserUtil.parse("SELECT * FROM MY_TABLE1");
Select selectStatement = (Select) statement;
TablesNamesFinder tablesNamesFinder = new TablesNamesFinder();
List<String> tableList = tablesNamesFinder.getTableList(selectStatement);

select a from tab1, tab2
select a, (select a from tab2) b from tab1
...