I have a bit of a tricky situation. I have a column that contains a pipe delimited set of numbers in numerous rows in a table. For example:

```
Courses
-------------------
1|2
1|2|3
1|2|8
10
11
11|12

```

What I want to achieve is to return rows where the number only appears once in my output.

Ideally, I want to try and carry this out using SQL rather than having to carry out checks at a web application level. Carrying out a DISTINCT does not achieve what I want.

The desired output would be:

```
Courses
-------------------
1
2
3
8
10
11
12

```

I would appreciated if anyone can guide me in the right direction.

Thanks.