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A SQL problem

A SQL problem# Database - 数据库

c*k2004-01-28 08:01

1 楼

I have a problem in creating a SQL statement. Can anyone help me?
Suppose I have a table as below:
id min max
1 7 11
2 9 12
3 14 18
4 10 13
I would like to merge the min and max and finally get this:
min max
7 13
14 18
How can I create a SQL statement to get that? Is it possible? Thanks in
advance!

b*l2004-01-28 08:01

2 楼

select min(min), min(max) from table
union
select max(min), max(max) from table

【在 c********k 的大作中提到】

: I have a problem in creating a SQL statement. Can anyone help me?
: Suppose I have a table as below:
: id min max
: 1 7 11
: 2 9 12
: 3 14 18
: 4 10 13
: I would like to merge the min and max and finally get this:
: min max
: 7 13

c*k2004-01-28 08:01

3 楼

No. I didn't mean that. I mean
[7, 11] U [9, 12] U [14, 18] U [10, 13] = [7, 13] U [14, 18]
It is possible there are much more rows in that table, and then the
result will not be only two rows.

【在 b******l 的大作中提到】

: select min(min), min(max) from table
: union
: select max(min), max(max) from table

n*a2004-01-28 08:01

4 楼

Explain your U operator. How does it work?????
Or give more examples, like another data set
where the final result is more than 2 rows.

【在 c********k 的大作中提到】

: No. I didn't mean that. I mean
: [7, 11] U [9, 12] U [14, 18] U [10, 13] = [7, 13] U [14, 18]
: It is possible there are much more rows in that table, and then the
: result will not be only two rows.

k*t2004-01-28 08:01

5 楼

好象是数集里面的算符

Explain your U operator. How does it work?????
Or give more examples, like another data set
where the final result is more than 2 rows.

【在 n********a 的大作中提到】

:
: Explain your U operator. How does it work?????
: Or give more examples, like another data set
: where the final result is more than 2 rows.

c*k2004-01-28 08:01

6 楼

Yes, set union operator

【在 k******t 的大作中提到】

: 好象是数集里面的算符
:
: Explain your U operator. How does it work?????
: Or give more examples, like another data set
: where the final result is more than 2 rows.

k*t2004-01-28 08:01

7 楼

i guess you need not only sql query

【在 c********k 的大作中提到】

: Yes, set union operator