在 bigquery 中将罗马数字转换为阿拉伯数字的最佳方法是什么？

Question

如题。我想到的最好的事情是使用基本的 REPLACE 函数，但它会失败，除了 I、V、X 等更复杂的

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我的数据中的罗马数字位于字符串的末尾，因此基于著名电影速度与激情我的数据如下所示：

movie
Fast & Furious I
Fast & Furious II
Fast & Furious III
Fast & Furious IV
Fast & Furious V
Fast & Furious VI
Fast & Furious VII

Answer 1

The Roman numerals in my data are located at the end of the string

考虑以下方法（以及除您之外的一些虚拟数据）

create temp function deromanize (number STRING) returns STRING 
language js as '''
  var number = number.toUpperCase(),
  validator = /^M*(?:D?C{0,3}|C[MD])(?:L?X{0,3}|X[CL])(?:V?I{0,3}|I[XV])$/,
  token = /[MDLV]|C[MD]?|X[CL]?|I[XV]?/g,
  key = {M:1000,CM:900,D:500,CD:400,C:100,XC:90,L:50,XL:40,X:10,IX:9,V:5,IV:4,I:1},
  num = 0, m;
  if (!(number && validator.test(number))) return false;
  while (m = token.exec(number)) num += key[m[0]];
  return num;
''';
with your_table as (
  select 'Fast & Furious I' movie union all
  select 'Fast & Furious II' union all
  select 'Fast & Furious III' union all
  select 'Fast & Furious IV' union all
  select 'Fast & Furious V' union all
  select 'Fast & Furious VI' union all
  select 'Fast & Furious VII' union all
  select 'Fast & Furious XXXIX' union all
  select 'Fast & Furious LXXI' union all
  select 'Fast & Furious MDCCLXXIV' 
)
select movie, 
  replace(movie, roman_number, deromanize(roman_number)) converted_title
from your_table, 
unnest([struct(array_reverse(split(movie, ' '))[offset(0)] as roman_number)])

有输出

在 bigquery 中将罗马数字转换为阿拉伯数字的最佳方法是什么？

What is the best way of converting roman numerals to arabic ones in bigquery?

sql

string

replace

google-bigquery