sql子查询聚合

实例sql: SELECT a.*, (SELECT b.id, SUM(b.num) FROM table2 AS b GROUP BY b.id HAVING b.id=a.id) AS sumNum FROM table1 AS a;
请问这种dsl请问该如何写? sql需要做分页
现在的type设计是table1为主文档, table2为嵌套文档