子查询将返回每行中每个表的计数。当将其用作引用表时，count（*）将仅返回子查询生成的行数，（在您的情况下始终为2，因为您有两个来自子查询的引用行）。您可以使用sum（）函数将每列中的结果相加。您可以尝试使用下面的查询，看看这是否是您所期望的结果吗？

• MYSQL版本-

SELECT sum(total_records) as final_count
FROM (
  SELECT COUNT(*) AS total_records
  FROM tbl1
  WHERE version_key = '100047'
 UNION ALL
 SELECT COUNT(*) AS total_records
 FROM tbl2
 WHERE version_key = '100047'
) as final_table having final_count = 5;

字符串

• 编辑2 -
  添加Oracle数据库查询

SELECT sum(total_records) as final_count
FROM (
  SELECT COUNT(*) AS total_records
  FROM tbl1
  WHERE version_key = '100047'
 UNION ALL
 SELECT COUNT(*) AS total_records
 FROM tbl2
 WHERE version_key = '100047'
) having sum(total_records) = 5;

型
希望这有帮助