google-bigquery - 谷歌专利大查询前向引用

Question

我想获取引用 2003 年至 2015 年间提交的所有美国专利的专利列表（公开号、申请日期等）。不知道出了什么问题，但我当前的代码（如下）没有返回任何结果。有人可以帮我修改代码吗？

SELECT c.publication_number AS Pub, c.category AS Cat, c.filing_date AS Date, p.publication_number AS Citedby, p.filing_date AS Cited_Date 
FROM `patents-public-data.patents.publications` AS p, UNNEST(citation) AS c 
WHERE c.publication_number LIKE ('US%') AND (c.filing_date BETWEEN 20030101 AND 20041231);

非常感谢您的帮助。

Answer 1

它正在发生，因为citation.filing_date每一0行都有价值。查看 JSON 输出文件和一个Date字段：

[
  {
    "Citedby": "US-2014313399-A1",
    "Cited_Date": "20140630",
    "Pub": "US-8792047-B2",
    "Cat": "PRS",
    "Date": "0"
  },
  {
    "Citedby": "US-2013120526-A1",
    "Cited_Date": "20120731",
    "Pub": "US-2011134210-A1",
    "Cat": "PRS",
    "Date": "0"
  },
  {
    "Citedby": "US-2013242999-A1",
    "Cited_Date": "20120530",
    "Pub": "US-7616646-B1",
    "Cat": "PRS",
    "Date": "0"
  },

你不应该使用(c.filing_date BETWEEN 20030101 AND 20041231)inWHERE子句：

SELECT p.publication_number AS Citedby, p.filing_date AS Cited_Date, c.publication_number AS Pub, c.category AS Cat, c.filing_date AS Date
FROM `patents-public-data.patents.publications` AS p, UNNEST(citation) AS c 
WHERE c.publication_number LIKE ('US%');

它打印出专利列表。或者您可以添加(p.filing_date BETWEEN 20030101 AND 20151231)，但请记住，这publications.filing_date不是citation.filing_date。

我希望它有所帮助。