显示实例拥有哪些属性的查询，超出属性的超集

Question

我在 Bigquery 中有一个包含两个 table 的关系数据集。

第一个 table 保存客户数据

+-------------+--------+
| Customer ID | Name   |
+-------------+--------+
| 1           | Bob    |
+-------------+--------+
| 2           | Jenny  |
+-------------+--------+
| 3           | Janice |
+-------------+--------+

第二个 table 包含与第一个 table 中的客户关联的各种 name/value 对：

+-------------+----------+-------+
| Customer ID | Category | Value |
+-------------+----------+-------+
| 1           | A        | A     |
+-------------+----------+-------+
| 1           | A        | B     |
+-------------+----------+-------+
| 1           | B        | A     |
+-------------+----------+-------+
| 2           | B        | B     |
+-------------+----------+-------+

我想生成一个报告来枚举每个客户，并在 table 2 中找到的每个 name:value 下设置一个 TRUE，例如：

+-------------+------+------+-----+------+------+
| Customer ID | A:A  | A:B  | A:C | B:A  | B:B  |
+-------------+------+------+-----+------+------+
| 1           | TRUE | TRUE |     | TRUE |      |
+-------------+------+------+-----+------+------+
| 2           |      |      |     |      | TRUE |
+-------------+------+------+-----+------+------+
| 3           |      |      |     |      |      |
+-------------+------+------+-----+------+------+

我已尝试将每个 category:value 组合指定为我的 select 语句

中的列

select
  customer id,
  a:a, 
  a:b, 
  a:c, 
  b:a,
  b:b 
from 
  table_1 t1
join 
  table_2 t2 
on
  t1.customer_id = t2.customer_id

但这没有给我任何帮助，因为一旦找到值，我不知道如何获取查询以将单元格设置为 TRUE。

抱歉，如果这很明显，我是 SQL 的新手。

Answer 1

您需要某种聚合，例如：

select t1.customer_id,
       bool_or(t2.category = 'a' and t2.value = 'a') as a_a,
       bool_or(t2.category = 'a' and t2.value = 'b') as a_b,
       bool_or(t2.category = 'a' and t2.value = 'c') as a_c,
       bool_or(t2.category = 'b' and t2.value = 'a') as b_a,
       bool_or(t2.category = 'b' and t2.value = 'b') as b_b
from table_1 t1 join
     table_2 t2 
     on t1.customer_id = t2.customer_id  
group by t1.customer_id;

Answer 2

以下适用于 BigQuery 标准 SQL

#standardSQL
SELECT customer_id,
  LOGICAL_OR((category, value) = ('A', 'A')) AS a_a,
  LOGICAL_OR((category, value) = ('A', 'B')) AS a_b,
  LOGICAL_OR((category, value) = ('A', 'C')) AS a_c,
  LOGICAL_OR((category, value) = ('B', 'A')) AS b_a,
  LOGICAL_OR((category, value) = ('B', 'B')) AS b_b
FROM `project.dataset.table1`  
JOIN `project.dataset.table2`
USING (customer_id)
GROUP BY customer_id

您可以使用您问题中的示例数据来测试和使用上面的示例，如下例所示

#standardSQL
WITH `project.dataset.table1` AS (
  SELECT 1 Customer_ID, 'Bob' Name UNION ALL
  SELECT 2, 'Jenny' UNION ALL
  SELECT 3, 'Janice' 
), `project.dataset.table2` AS (
  SELECT 1 Customer_ID, 'A' Category, 'A' Value UNION ALL
  SELECT 1, 'A', 'B' UNION ALL
  SELECT 1, 'B', 'A' UNION ALL
  SELECT 2, 'B', 'B' 
)
SELECT customer_id,
  LOGICAL_OR((category, value) = ('A', 'A')) AS a_a,
  LOGICAL_OR((category, value) = ('A', 'B')) AS a_b,
  LOGICAL_OR((category, value) = ('A', 'C')) AS a_c,
  LOGICAL_OR((category, value) = ('B', 'A')) AS b_a,
  LOGICAL_OR((category, value) = ('B', 'B')) AS b_b
FROM `project.dataset.table1`  
JOIN `project.dataset.table2`
USING (customer_id)
GROUP BY customer_id

结果

Row customer_id a_a     a_b     a_c     b_a     b_b  
1   1           true    true    false   true    false    
2   2           false   false   false   false   true

如果您 need/want 输出与您的问题完全相同 - 您可以使用以下调整后的版本

#standardSQL
SELECT customer_id,
  IF(LOGICAL_OR((category, value) = ('A', 'A')), 'TRUE', '') AS a_a,
  IF(LOGICAL_OR((category, value) = ('A', 'B')), 'TRUE', '') AS a_b,
  IF(LOGICAL_OR((category, value) = ('A', 'C')), 'TRUE', '') AS a_c,
  IF(LOGICAL_OR((category, value) = ('B', 'A')), 'TRUE', '') AS b_a,
  IF(LOGICAL_OR((category, value) = ('B', 'B')), 'TRUE', '') AS b_b
FROM `project.dataset.table1`  
JOIN `project.dataset.table2`
USING (customer_id)
GROUP BY customer_id

结果

Row customer_id a_a     a_b     a_c     b_a     b_b  
1   1           TRUE    TRUE            TRUE         
2   2                                           TRUE

注意：在上面的示例中 - 您实际上不需要连接，因为您没有使用表 1 中的字段而不是用作过滤器（仅显示表 1 中的用户）

显示实例拥有哪些属性的查询，超出属性的超集

Query that displays which attributes an instance possesses, out of a superset of attributes

sql

report

name-value

google-bigquery