如何将字符串拆分为mysql中的另一个表并从中获取信息

Question

我有一个系统可以为存储在列中的每个句子分配分数：

表 1：word_scores

word       score
this       3
is         4
a          5
test       1
another    0
sentence   8

表2：句子（得分列根据表1计算）

sentence           score
this is a test     13
another sentence   8
this is            7

现在我需要1.将每个句子提取到PHP中，2.然后将字符串拆分为单词，3.然后捕获每个单词的分数，4.然后计算word_scores的总和

是否可以在mysql中计算句子分数？

Answer 1

基本上是的，有一种方法可以做到这一点。

这是一个选择语句，它为您提供每个句子的分数

SELECT
PARSED_SENTENCES.sentence, SUM(COALESCE(WordScores.score, 0)) score
FROM (
     SELECT sentence,
     SUBSTRING(
          sentence
          FROM CASE
               WHEN INDEX_TABLE.POS = 1 THEN 1
               ELSE INDEX_TABLE.POS + 1
               END
          FOR CASE LOCATE(' ', sentence, INDEX_TABLE.POS + 1)
              WHEN 0 THEN CHARACTER_LENGTH(sentence) + 1
              ELSE LOCATE(' ', sentence, INDEX_TABLE.POS + 1)
              END
              - CASE
                WHEN INDEX_TABLE.POS = 1 THEN 1
                ELSE INDEX_TABLE.POS + 1
                END
     ) AS word
     FROM SentenceScores
     INNER JOIN (
          SELECT @rownum:=@rownum+1 POS
          FROM (
             SELECT 0 UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3
             UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6
             UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9
          ) a, (
             SELECT 0 UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3
             UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6
             UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9
          ) b, (
             SELECT 0 UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3
             UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6
             UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9
          ) c, (SELECT @rownum:=0) r
     ) INDEX_TABLE
     ON INDEX_TABLE.POS <= CHAR_LENGTH(SentenceScores.sentence)
     AND (
          INDEX_TABLE.POS = 1
          OR SUBSTRING(SentenceScores.sentence FROM INDEX_TABLE.POS FOR 1) = ' '
     )
) AS PARSED_SENTENCES
LEFT OUTER JOIN WordScores
ON PARSED_SENTENCES.word = WordScores.word
GROUP BY PARSED_SENTENCES.sentence;

您应该能够将其转换为更新语句，以便您可以计算分数并将它们同时应用于表格。

根据下面的评论讨论，如果您想用静态数字表替换 numbers-table 子查询，您可以替换查询的这一部分：

 INNER JOIN (
      SELECT @rownum:=@rownum+1 POS
      FROM (
         SELECT 0 UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3
         UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6
         UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9
      ) a, (
         SELECT 0 UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3
         UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6
         UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9
      ) b, (
         SELECT 0 UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3
         UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6
         UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9
      ) c, (SELECT @rownum:=0) r
 ) INDEX_TABLE

只需：

INNER JOIN INDEX_TABLE

假设您的数字表和数字列与子查询中的名称相同，即 INDEX_TABLE 和 POS