需求：Mysql資料庫 有不同屬性的兩張表，需要進行按某個條件查詢，結果合併排序分頁。

讓產品把兩個表分成兩段展示各查各的，分開來。

產品經理說能實現：產品寫sql 聯合查詢， A UNION ALL B 。

那開發就處理後續排序分頁了。

dao層

@Query(nativeQuery = true,value = "SELECT re.id,re.i_amount,re.i_share,re.create_time,re.type,re.fund_id,re.role_id FROM ( " +
        "SELECT id AS id, i_amount AS i_amount, i_share AS i_share, create_time AS create_time , fund_id As fund_id , 0 AS role_id ,1 AS type " +
        "FROM f_project where project_id = :projectId " +
        "UNION ALL " +
        "SELECT id AS id, i_amount AS i_amount, i_share AS i_share, create_time AS create_time , 0 As fund_id , role_id AS role_id ,2 AS type " +
        "FROM l_project  where project_id = :projectId  ) re"
        ,countQuery = "SELECT count(re.id) FROM ( SELECT id  FROM f_project  where project_id = :projectId UNION ALL SELECT id  FROM l_project  where project_id = :projectId  )  as re")
Page<Map<String,Object>> find(@Param("projectId") long projectId, Pageable pageable);
 

service層呼叫 

Pageable pageable = PageRequest.of(pageQueryDto.getPage() - 1, pageQueryDto.getSize(), Sort.Direction.fromString(pageQueryDto.getDirection()), propertie);
Page<Map<String, Object>> page = projectRepository.find(projectId, pageable);