当文本字段是MS SQL Server 2000中返回字段的一部分时，如何选择不同的行？

I have a database-driven FAQ that is organised into sections and I am trying to get the section data for only those sections who have a question/answer associated with them.

我有一个数据库驱动的常见问题解答,它被组织成各个部分,我试图只获得那些有问题/答案的部分的部分数据。

Here is the schema:

这是架构:

|---------------------|      |----------------------|
|       Section       |      |       Quest-Ans      |
|---------------------|      |----------------------|
| PK | id(int)        |<--|  | PK     | id(int)     |
|    | title(varchar) |   |--| FK     | Sec_id(int) |
|    | desc(text)     |      |        | body(text)  |
|---------------------|      |----------------------|

When I try this query:

当我尝试这个查询时:

SELECT DISTINCT s.id, s.title, s.desc
FROM Section as s INNER JOIN Quest-Ans as q ON s.id = q.Sec_id

I get an error saying that DISCRETE cannot be applied to a text field. How can I get the data I want?

我收到一条错误消息,说DISCRETE无法应用于文本字段。我怎样才能获得我想要的数据?

If it matters, this is an SQL2000 database.

如果重要,这是一个SQL2000数据库。

EDIT:

Ok, so it seems like there are two ways to go about this. Either with EXISTS and a subquery in the where clause, or with the subquery in the inner join. Which is faster?

好的,所以似乎有两种方法可以解决这个问题。使用EXISTS和where子句中的子查询,或者使用内部联接中的子查询。哪个更快?

4 个解决方案

#1

This should do it:

这应该这样做:

SELECT s.id, s.title, s.desc
FROM Section as s 
WHERE EXISTS (SELECT * FROM Quest-Ans as q where q.Sec_id = s.id)

#2

select s.id, s.title, s.desc
from Section s 
inner join (select distinct sec_id from Quest-Ans) dqa on s.id = dqa.sec_id

#3

Try it:

SELECT s.Title, s.Desc
FROM Section as s
INNER JOIN (
  SELECT DISTINCT s.id
  FROM Section as s 
  INNER JOIN Quest-Ans as q ON s.id = q.Sec_id
) q ON s.Id = q.Id

#4

try CONVERT , DISTINCT CONVERT(VARCHAR(500), "text field")

尝试CONVERT,DISTINCT CONVERT(VARCHAR(500),“text field”)

#1