如何在 Looker 中按日期计算状态变化？

Posted 2023-03-31

【中文标题】如何在 Looker 中按日期计算状态变化？

【英文标题】：How to count state changes by date in Looker?

【发布时间】：2021-01-18 09:22:14

【问题描述】：

我在 BigQuery 中有一个包含创建日期和上次修改日期的任务。如果可能的话，我希望能够在同一个表中按日期报告任务打开和任务关闭事件的数量。

view: tasks 
  derived_table: 
    sql:
        SELECT *
        FROM UNNEST(ARRAY<STRUCT<CREATED_DATE DATE, LAST_MODIFIED DATE, ID INT64, STATE STRING>>[
        ('2020-12-01', '2020-12-01', 1, "OPEN"),
        ('2020-12-01', '2020-12-03', 2, "CLOSED"),
        ('2020-12-02', '2020-12-03', 3, "CLOSED"),
        ('2020-12-03', '2020-12-05', 4, "OPEN"),
        ('2020-12-05', '2020-12-05', 5, "CLOSED")])
      ;;
  
  dimension_group: created 
    type: time
    datatype: date
    sql: $TABLE.created_date ;;
  
  dimension_group: last_modified 
    type: time
    datatype: date
    sql: $TABLE.last_modified ;;
  
  dimension: id 
    type: number
  
  dimension: state 
    type: string
  
  measure: number_of_tasks 
    type: count_distinct
    sql: $id ;;
  
  measure: number_of_open_tasks 
    type: count_distinct
    sql: $id ;;
    filters: 
      field: "state"
      value: "OPEN"
    
  
  measure: number_of_closed_tasks 
    type: count_distinct
    sql: $id ;;
    filters: 
      field: "state"
      value: "CLOSED"
    
  

explore: tasks 

我可以使用创建日期获取打开任务的数量。

我可以通过计算任务来获得关闭的任务数，其中最后修改日期在聚合期间并且状态为关闭，并带有过滤度量。

但是，如果我尝试将这些组合在一个表中，我会为每个日期组合得到一行。

如何按日期计算任务状态更改？

Date	Number of Opened Tasks	Number of Closed Tasks
2020-12-01	2	0
2020-12-02	1	0
2020-12-03	1	2
2020-12-04	0	0
2020-12-05	1	1

【参考方案1】：

一位同事提出了解决方案。将任务表堆叠在自身上会为每个任务创建（最多）两行。

view: tasks 
  derived_table: 
    sql:
        WITH tab AS (
          SELECT *
          FROM UNNEST(ARRAY<STRUCT<CREATED_DATE DATE, LAST_MODIFIED DATE, ID INT64, STATE STRING>>[
          ('2020-12-01', '2020-12-01', 1, "OPEN"),
          ('2020-12-01', '2020-12-03', 2, "CLOSED"),
          ('2020-12-02', '2020-12-03', 3, "CLOSED"),
          ('2020-12-03', '2020-12-05', 4, "OPEN"),
          ('2020-12-05', '2020-12-05', 5, "CLOSED")])
        )
        SELECT *, 1 open_count, 0 closed_count, created_date AS action_date 
        FROM tab
        UNION DISTINCT
        SELECT *, 0 open_count, 1 closed_count, last_modified AS action_date 
        FROM tab
        WHERE state = "CLOSED"
      ;;
  
  dimension_group: created 
    type: time
    datatype: date
    sql: $TABLE.created_date ;;
  
  dimension_group: last_modified 
    type: time
    datatype: date
    sql: $TABLE.last_modified ;;
  
  dimension_group: action 
    type: time
    datatype: date
    sql: $TABLE.action_date ;;
  
  dimension: id 
    type: number
  
  dimension: state 
    type: string
  
  dimension: open_count 
    type: number
    hidden: yes
  
  dimension: closed_count 
    type: number
    hidden: yes
  
  measure: number_opened
    type: sum
    sql: $open_count ;;
  
  measure: number_closed 
    type: sum
    sql: $closed_count ;;
  

explore: tasks 

然后可以计算打开和关闭的标签。