MySQL Basic Select Query

I have a MySQL table called connections, with two unsigned integer fields, called a and b (which are unique), with the following values (and many more).

A, B

1, 2

1, 3

8, 9

4, 6

5, 1

3, 7

1 is connected to 2, 3, and 5. 3 is connected to 7. I have been struggling to come up with a query that will select all connections for a given number. For example, number 2 woul开发者_Go百科d return the following...

1

2

3

5

7

Number 5 would also return...

1

2

3

5

7

If someone can help me out I would greatly appreciate it. I have been stuck on this for the last week, and have made little to no progress. :(

Thanks in advance!

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I don't think your problem cannot be solved with a single select statement. Solution requires multipass scan of your tables to arrive at the final answer

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It sounds like you need a hierarchical query here, which exists in Oracle, but I don't think it is in mySql. Here is a link to an article which explains how to get hierarchical functionality in mySql. I have not tried it myself.

http://explainextended.com/2009/03/17/hierarchical-queries-in-mysql/