1 
Table 1:Domain Link Result
======================================================================
||Column1(words)     ||Column2(links)    ||Column3(frequency)       ||
======================================================================
    1                   1                   Any Number
    2                   1                   Any Number
    3                   1                   Any Number
    4                   1                   Any Number
    1                   2                   Any Number
    2                   2                   Any Number
    3                   2                   Any Number
    4                   2                   Any Number


Table 2:Sub Link Result
======================================================================
||Column1(words)     ||Column2(sublinks)    ||Column3(frequency)    ||
======================================================================
    1                   a                   Any Number
    2                   b                   Any Number
    3                   c                   Any Number
    4                   d                   Any Number
    1                   e                   Any Number
    2                   f                   Any Number
    3                   g                   Any Number
    4                   h                   Any Number

And so on.

在上述场景中，用户输入了 4 个单词和 2 个域链接。现在，在域链接和子链接上计算 4 个关键字的频率，并存储在单独的表中，如上所示。我想要一个如下的汇总结果：

Table 3:Final Result
==================================================================================
||Column1(words)     ||Column2(Domain links)    ||Column3(Total frequency)      ||
==================================================================================
Row1:    1              1                    Total of frequency in both tables
                        2                    for word "1"   
----------------------------------------------------------------------------------
Row2:    2              1                    Total of frequency in both tables
                        2                    for word "2"   
----------------------------------------------------------------------------------
Row3:    3              1                    Total of frequency in both tables
                        2                    for word "3"   
----------------------------------------------------------------------------------
Row4:    4              1                    Total of frequency in both tables
                        2                    for word "4"   
----------------------------------------------------------------------------------

我在 MySQL 中尝试了以下查询：

SELECT t.`keyword`, t.`link` SUM( t.`frequency` ) AS total
FROM (

SELECT `frequency`
FROM `domain_link_result`
WHERE `keyword` = 'national'
UNION ALL
SELECT `frequency`
FROM `sub_link_result`
WHERE `keyword` = 'national'
)t GROUP BY `keyword`

但在最终结果的第 2 列中，我只得到第一个链接，而不是第 1 行的两个链接。如何获得两个链接或用户在一行中输入的任意数量的链接？

单词和链接具有VARCHAR类型，频率具有INT类型。

4

1 回答 1

1

如果您想将多行合并为一行并且仍然能够看到信息，则必须使用GROUP_CONCAT

http://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html#function_group-concat

这将输出以逗号分隔的折叠值，即：字符串。如果您需要单独的值，可以在您的编程语言中拆分此字符串。

您的查询看起来像这样

SELECT keyword, GROUP_CONCAT(links), SUM(frequency)

FROM (subquery)

GROUP BY keyword

这将输出如下内容：

==================================================================================
||Column1(words)     ||Column2(Domain links)    ||Column3(Total frequency)      ||
==================================================================================
Row1:    1              1,2                     sum of freq.
----------------------------------------------------------------------------------
Row2:    2              1,2                     sum of freq.
----------------------------------------------------------------------------------
Row3:    3              1,2                     sum of freq.
----------------------------------------------------------------------------------
Row4:    4              1,2                     sum of freq.

编辑：为您的查询提供额外帮助

您的查询对我来说有点令人困惑。尝试使用 JOIN 方法：

SELECT domain_link_results.word AS word,
       GROUP_CONCAT(domain_link_results.links) AS domain_links,
       domain_link_results.frequency + sub_link_results.frequency AS total_frequency

FROM domain_link_results

INNER JOIN sub_link_results
        ON domain_link_results.word = sub_link_results.word

WHERE domain_link_results.word = "national"

GROUP BY domain_link_results.word

另一方面，最好将所有链接放在同一个表中，并使用一个额外的字段来确定它是域链接还是子链接。在不了解您的系统的情况下很难说。

于 2013-03-26T20:46:38.303 回答