Hive 配置单元嵌套select语句

我正在尝试在配置单元中执行嵌套的select语句-

select col1, (select COUNT(*) as cnt from table2) , col2 from table1;

当我运行上面的查询时，我得到下面的异常-

FAILED: ParseException line 1:8 cannot recognize input near 'select' 'COUNT' '(' in expression specification

我还尝试将select count（*）分配给hivevar并在查询中使用它。但是，我还是遇到了同样的问题

set hivevar:cnt=select COUNT(*) as cnt from table2;
select col1, ${hivevar:cnt} , col2 from table1;

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您可以对主表使用

WITH

子句和

交叉连接

WITH t AS (SELECT COUNT (*) AS ct FROM table2)
SELECT s.col1, t.ct, s.col2
  FROM table1 s CROSS JOIN t