mysql联合搜索（多个表）维护相关性

Question

我有多个表，具有不同的列，相应地设置全文索引。 如果我只想搜索一个表，因为得分会按相关性对数据进行排序，这没有问题。 但是我有多个表，我使用UNION来执行以下sql SELECT语句：

$this->dbi->prepare("
    SELECT `id`,'".PRE."pages' as `table`, MATCH(`title`,`content`) AGAINST (?) AS `score` FROM `".PRE."pages` WHERE MATCH(`title`,`content`) AGAINST (?)
    UNION SELECT `id`,'".PRE."news' as `table`, MATCH(`title`,`content`) AGAINST (?) AS `score` FROM `".PRE."news` WHERE MATCH(`title`,`content`) AGAINST (?)
    UNION SELECT `id`,'".PRE."comments' as `table`, MATCH(`title`, `content`) AGAINST (?) AS `score` FROM `".PRE."comments` WHERE MATCH(`title`, `content`) AGAINST(?)
    UNION SELECT `id`,'".PRE."auction_auto' as `table`, MATCH(`manufacturer`,`model`,`location`,`other`,`contact`) AGAINST (?) AS `score` FROM `".PRE."auction_auto` WHERE MATCH(`manufacturer`,`model`,`location`,`other`,`contact`) AGAINST (?)
;")->...

我怎样才能对这些表有相关性？ 现在无论分数数据将按照表格的顺序显示我做的选择。

谢谢。

对于autor自己可能的解决方案，请参阅此链接

Answer 1

两种选择：

1. 创建一个视图，允许您通过从视图中进行选择来进行排序。
2. 将您的查询放入（嵌套查询作为表与as），并按顺序排序。 请参阅： http ： //dev.mysql.com/doc/refman/5.0/en/from-clause-subqueries.html

以下是我自己的数据示例（仅用于示例目的）：

select * from
(
  (select * from products where products_id >10)
  UNION
  (select * from products where products_id <= 10)
)
as SOURCE
order by products_id

因此，使用您自己的示例，它将类似于：

    $this->dbi->prepare("
select * from 
(
        SELECT `id`,'".PRE."pages' as `table`, MATCH(`title`,`content`) AGAINST (?) AS `score` FROM `".PRE."pages` WHERE MATCH(`title`,`content`) AGAINST (?)
        UNION SELECT `id`,'".PRE."news' as `table`, MATCH(`title`,`content`) AGAINST (?) AS `score` FROM `".PRE."news` WHERE MATCH(`title`,`content`) AGAINST (?)
        UNION SELECT `id`,'".PRE."comments' as `table`, MATCH(`title`, `content`) AGAINST (?) AS `score` FROM `".PRE."comments` WHERE MATCH(`title`, `content`) AGAINST(?)
        UNION SELECT `id`,'".PRE."auction_auto' as `table`, MATCH(`manufacturer`,`model`,`location`,`other`,`contact`) AGAINST (?) AS `score` FROM `".PRE."auction_auto` WHERE MATCH(`manufacturer`,`model`,`location`,`other`,`contact`) AGAINST (?)
) as allTables order by `id`;")