1

我在 Bigquery 中有一个包含两个表的关系数据集。

第一个表保存客户数据

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

第二个表包含与第一个表中的客户关联的各种名称/值对：

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

我想生成一个枚举每个客户的报告，并在每个名称下设置一个 TRUE：在表 2 中找到它的值，例如：

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

我试图将每个类别：值组合指定为我的选择语句中的列

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

但这没有给我任何东西，因为一旦找到值，我不知道如何让查询将单元格设置为 TRUE。

如果这很明显，我很抱歉，我对 SQL 很陌生。

4

2 回答 2

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;
于 2019-04-12T16:33:34.060 回答
1

以下是 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进行测试，使用上面的示例数据，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

如果您需要/想要与您的问题完全相同的输出 - 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 - 您实际上并不需要连接，因为您没有使用 table1 中的字段而不是作为过滤器（仅显示 table1 中的用户）

于 2019-04-13T00:46:33.820 回答