How to sql-recursive statements work?

Question

I am trying to understand sql recursive statements, but it is really hard for me. For example:

enter image description here

Thats an exampe I am trying to understand and to write down the output.

Can sb pls explain me how this works, step by step?

greetings and thx in advance

maya

There is a highly detailed set of three examples here: http://walkingoncoals.blogspot.com/2009/12/fun-with-recursive-sql-part-1.html I also have [a blog post](http://adam-bernier.appspot.com/post/91001/recursive-sql-example) on the subject (specific to PostgreSQL). — mechanical_meat, Mar 04 '12 at 22:43

score 2 · Accepted Answer · answered Mar 04 '12 at 23:02

2

Also, see here - http://www.postgresql.org/docs/8.4/static/queries-with.html, where the steps of the recursive query evaluation are described.

answered Mar 04 '12 at 23:02

devdigital

score 0 · Answer 2 · answered Sep 05 '12 at 03:06

0

The UNION ALL portion gets recursed until it returns no more records. I don't know if you can have multiple UNION ALL portions.

answered Sep 05 '12 at 03:06

Chris Travers

2 Answers2