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我有一个表来计算单词出现次数WORD_COUNT(WORD, TOTAL)，该表在另一个表的触发器中更新。这是在这样的分层查询中完成的：

创建单词和总数=1：

INSERT INTO WORD_COUNT(TOTAL, WORD)
  SELECT 1, TRANSLATE(regexp_substr(:NEW.TWEET, '[^[:punct:]|[:space:]]+', 1, level),
                            'áéíóúÁÉÍÓÚ',
                            'aeiouAEIOU')
  FROM DUAL
  WHERE LENGTH(regexp_substr(:NEW.TWEET, '[^[:punct:]|[:space:]]+', 1, level)) >= 5
  CONNECT BY regexp_substr(:NEW.TWEET, '[^[:punct:]|[:space:]]+', 1, level) IS NOT NULL;

这项工作非常完美，它将一个短语（推文）拆分为单词并将它们插入到 WORD_COUNT 中。

现在的问题是，当我想增加重复键的总数（WORD 是主键）时，我需要添加一个ON DUPLICATE KEY似乎与子句不太吻合的CONNECT BY子句。

此查询无法编译：

INSERT INTO WORD_COUNT(TOTAL, WORD)
  SELECT 1, TRANSLATE(regexp_substr(:NEW.TWEET, '[^[:punct:]|[:space:]]+', 1, level),
                            'áéíóúÁÉÍÓÚ',
                            'aeiouAEIOU')
  FROM DUAL
  WHERE LENGTH(regexp_substr(:NEW.TWEET, '[^[:punct:]|[:space:]]+', 1, level)) >= 5
  CONNECT BY regexp_substr(:NEW.TWEET, '[^[:punct:]|[:space:]]+', 1, level) IS NOT NULL
  ON DUPLICATE KEY UPDATE TOTAL=TOTAL+1;

而这个也不是：

INSERT INTO WORD_COUNT(TOTAL, WORD)
WITH WORDS(WORD) AS
 (SELECT DISTINCT 1,
         TRANSLATE(regexp_substr(:NEW.TWEET, '[^[:punct:]|[:space:]]+', 1, level),
                            'áéíóúÁÉÍÓÚ',
                            'aeiouAEIOU')
    FROM DUAL
    WHERE LENGTH(regexp_substr(:NEW.TWEET, '[^[:punct:]|[:space:]]+', 1, level)) >= 5
    CONNECT BY regexp_substr(:NEW.TWEET, '[^[:punct:]|[:space:]]+', 1, level) IS NOT NULL)
SELECT WORD FROM WORD_COUNT
ON DUPLICATE KEY UPDATE TOTAL = TOTAL + 1;

由于这发生在一个高流量表的触发器中，我想在一个查询中解决这个问题，但也许是时候考虑一​​个中间表了，是吗？

谢谢

4

2 回答 2

2

这应该可以使用合并：

MERGE INTO WORD_COUNT WC
USING 
(
  SELECT DISTINCT 1,
         TRANSLATE(regexp_substr(:NEW.TWEET, '[^[:punct:]|[:space:]]+', 1, level),
                            'áéíóúÁÉÍÓÚ',
                            'aeiouAEIOU')
    FROM DUAL
    WHERE LENGTH(regexp_substr(:NEW.TWEET, '[^[:punct:]|[:space:]]+', 1, level)) >= 5
    CONNECT BY regexp_substr(:NEW.TWEET, '[^[:punct:]|[:space:]]+', 1, level) IS NOT NULL
) NW
ON (WC.WORD = NW.WORD)
WHEN MATCHED THEN UPDATE SET WC.TOTAL = WC.TOTAL + 1
WHEN NOT MATCHED THEN INSERT(TOTAL, WORD) VALUES(NW.TOTAL, NW.WORD);
于 2014-03-04T08:57:47.167 回答
0

As I know oracle db doesn't support "on duplicate key" clause. You should try use MERGE clause.

I think it's similar question to: Oracle: ON DUPLICATE KEY UPDATE

于 2014-03-04T09:02:42.773 回答