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javascript - 字符串匹配算法中的引用错误

问题描述

我已经为两个字符串列之间的字符串匹配百分比（0-1）创建了 UDF，并且在执行以下查询时遇到此错误。我想执行此代码以获取名称匹配算法以显示从 0- 开始的概率算法1 值。我创建了两个函数并在该函数中定义了两个字符串列。

CREATE OR REPLACE FUNCTION `rep-ds-us.nboorla.similarity`(name STRING, to_name STRING) RETURNS INT64 LANGUAGE js AS """
/*
 * Data Quality Function - Fuzzy Matching
 * dq_fm_LevenshteinDistance
 * Based off of https://gist.github.com/andrei-m/982927
 * input: Two strings to compare the edit distance of.
 * returns: Integer of the edit distance.
 */
var a = in_a.toLowerCase();
var b = in_b.toLowerCase();
  
if(a.length == 0) return b.length; 
if(b.length == 0) return a.length;
var matrix = [];
// increment along the first column of each row
var i;
for(i = 0; i <= b.length; i++){
  matrix[i] = [i];
}
// increment each column in the first row
var j;
for(j = 0; j <= a.length; j++){
  matrix[0][j] = j;
}
// Fill in the rest of the matrix
for(i = 1; i <= b.length; i++){
  for(j = 1; j <= a.length; j++){
    if(b.charAt(i-1) == a.charAt(j-1)){
      matrix[i][j] = matrix[i-1][j-1];
    } else {
      matrix[i][j] = 
        Math.min(matrix[i-1][j-1] + 1, // substitution
        Math.min(matrix[i][j-1] + 1, // insertion
        matrix[i-1][j] + 1)); // deletion
    }
  }
}
return matrix[b.length][a.length];
""";

CREATE OR REPLACE FUNCTION `rep-ds-us.nboorla.conf`(name STRING, to_name STRING) AS (
/*
 * Data Quality Function - Fuzzy Matching
 * dq_fm_ldist_ratio
 * input: Two strings to compare.
 * returns: The Levenshtein similarity ratio.
 */
(LENGTH(name) + LENGTH(to_name) -  `rep-ds-us.nboorla.similarity`(name, to_name)) 
  / (LENGTH(name) + LENGTH(to_name))
);

select t1.name,t2.to_name,`rep-ds-us.nboorla.conf`(t1.name,t2.to_name)
from `rep-ds-us.r4e_mongo.ratings` t1 
 JOIN `rep-ds-us.r4e_mongo.mongo_repbiz_request_reviews` t2 on t2.id=t1.id 
 limit 10

但它给了我以下错误

Query error: ReferenceError: in_a is not defined at UDF$1(STRING, STRING) line 9, columns 8-9 at [52:1]

我错过了什么吗？

标签： javascriptgoogle-bigqueryuser-defined-functions

解决方案

它给了我以下错误

查询错误：ReferenceError: in_a is not defined at UDF$1(STRING, STRING) line 9, columns 8-9 at [52:1]
我错过了什么吗？

您至少应该为您的第一个函数修复签名，如下所示

CREATE OR REPLACE FUNCTION `rep-ds-us.nboorla.similarity`(in_a STRING, in_b STRING) RETURNS INT64 LANGUAGE js AS """

笔记; 以上回答了您当前的具体问题，可能无法解决与您使用的代码相关的任何未来问题。

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