当我试图取消数组字段时，BigQuery中的“列名称ID是不明确的”错误

Question

我有一个像这样的模式的BigQuery表（为了简洁起见列出了非常重要的字段）：

id [STRING]
products [RECORD]
products.id [STRING]

我正在尝试执行查询并同时获取id和products.id：

SELECT 
  id as transaction_id,
  products.id as product_id
FROM 
  `my-project.set.transactions_table`,
  UNNEST(products) as products

并收到错误：Column name id is ambiguous at [2:3]

如何消除歧义？

Answer 1

你的第一个id是含糊不清的。只需要添加表源

SELECT 
  transactions.id as transaction_id,
  products.id as product_id
FROM 
  `my-project.set.transactions_table` as transactions,
  UNNEST(products) as products