Question

我正在尝试构建一个查询来查看我们的帮助台系统中的票证。我想在主题或说明字段中搜索几个关键字，即“电子邮件”，并返回每个关键字的计数。下面是一个示例表。还有一个类别行，但它没有很好地维护，因此大多数字段都是空的。

  ID |       Subject         | Description
-----+-------------------------------------
   1 | hellloooo             | can't send email
   2 | email down?           | can't get to intranet
   3 | Phone trouble         | can't check voicemail
   4 | Using my phone        | I don't know how
   5 | Need new mouse        | please replace
   6 | Mouse acting funny    | n/a
   7 | Intranet won't Load   | what's this plug do?
   8 | not getting voicemail | why not?

我想返回类似

的内容

Category   |   # of tickets
---------------------------
Email      |   3
Phone      |   2
Intranet   |   2

最简单的方法是什么？

Answer 1

您没有指定RDBMS，但以下内容适用于SQL Server

;with cte as
(
  select 'Email' Category
  UNION ALL
  select 'Phone'
  UNION ALL
  select 'Intranet'
)
select category, count(*)
from cte c
inner join tickets t
  on t.subject like '%' + c.category + '%'
  or t.description like '%' + c.category + '%'
group by category

请参阅SQL Fiddle with Demo

如果您要查询的类别列表较长，则可能需要考虑将其存储在单独的表中并加入表中。

编辑Sqlite，没有CTE所以你可以通过以下方式做我的例子（更新后使用正确的语法在SQLite中连接）：

select category, count(*)
from 
(
  select 'Email' Category
  UNION ALL
  select 'Phone'
  UNION ALL
  select 'Intranet'
) c
inner join tickets t
  on t.subject like '%' || c.category || '%'
  or t.description like '%' || c.category || '%'
group by category

请参阅SQL Fiddle with Demo

Answer 2

使用Microsoft SQL Server，我可能会这样做：

DECLARE @CategoryList TABLE (Category VARCHAR(MAX))

INSERT INTO @CategoryList VALUES ('Email')
INSERT INTO @CategoryList VALUES ('Phone')
INSERT INTO @CategoryList VALUES ('Intranet')

SELECT Category, COUNT(*) AS NumberOfTickets
FROM Tickets
INNER JOIN @CategoryList CategoryList ON Tickets.Subject LIKE '%' + CategoryList.Category + '%' OR Tickets.Description LIKE '%' + CategoryList.Category + '%'
GROUP BY Category

从多列计算多个LIKE结果？

2 个答案: