如何在数据透视中应用条件聚合函数？答案

【问题标题】：How to apply conditional aggregate function in a pivot?如何在数据透视中应用条件聚合函数？
【发布时间】：2018-01-24 00:01:50
【问题描述】：

我有以下查询：

SELECT "CASE_RECORD_ID",
  "OPEN_DT",
  "PENDING_DT",
  "CLOSED_DT"
FROM
  (SELECT case_record_id,
    workflow_status_cd,
    workflow_status_dt
  FROM case_workflow_status
  ) PIVOT ( MIN(workflow_status_dt) FOR workflow_status_cd IN ('O' AS open_dt, 'P' AS pending_dt, 'C' AS closed_dt) );

如何根据 workflow_status_cd 应用不同的聚合函数？我的非工作尝试如下：

SELECT "CASE_RECORD_ID",
    "OPEN_DT",
    "PENDING_DT",
    "CLOSED_DT"
  FROM
    (SELECT case_record_id,
      workflow_status_cd,
      workflow_status_dt
    FROM case_workflow_status
    ) 

    PIVOT (

    (
    CASE workflow_status_cd
        WHEN 'O' THEN MIN(workflow_status_dt)
        WHEN 'P' THEN MAX(workflow_status_dt)
        WHEN 'C' THEN MAX(workflow_status_dt)
    END
    )
      FOR workflow_status_cd IN ('O' AS open_dt, 'P' AS pending_dt, 'C' AS closed_dt) 
  );

【问题讨论】：

标签： sql oracle oracle11g

【解决方案1】：

只需使用适当的聚合函数和 CASE 语句来匹配适当的状态：

SELECT CASE_RECORD_ID,
       MIN( CASE WHEN workflow_status_cd = 'O' THEN workflow_status_dt END ) AS OPEN_DT,
       MAX( CASE WHEN workflow_status_cd = 'P' THEN workflow_status_dt END ) AS PENDING_DT,
       MAX( CASE WHEN workflow_status_cd = 'C' THEN workflow_status_dt END ) AS CLOSED_DT
FROM   case_workflow_status
GROUP BY CASE_RECORD_ID;

【讨论】：