oracle query alternating records - sql

Question

I have a table that looks like this:
SEQ TICKER INDUSTRY
1 AAPL 10
1 FB 10
1 IBM 10
1 CSCO 10
1 FEYE 20
1 F 20
2 JNJ 10
2 CMPQ 10
2 CYBR 10
2 PFPT 10
2 K 20
2 PANW 20
What I need is record with the same industry code, to alternate between the 1 & 2 records like this:
1 AAPL 10
2 IBM 10
1 FB 10
2 CSCO 10
1 FEYE 20
2 PANW 20
So basically, grouped by the same industry code, alternate between the 1 & 2 records.
Can't figure out how.

Answer 1

Use an analytic function to create a row number that starts over for each group (industry and sequence), then sort by that row number.
select seq, ticker, industry
,row_number() over (partition by industry, seq order by ticker)custom_order
from stocks
order by industry, custom_order, seq;
See this SQL Fiddle for a full example. (It doesn't perfectly match your example results but either your example results are incorrect or there's something else to this question I don't understand.)

Answer 2

Don't see how you arrived at the example result in your question, but this result:
| SEQ | TICKER | INDUSTRY |
|-----|--------|----------|
| 1 | AAPL | 10 |
| 2 | CMPQ | 10 |
| 1 | CSCO | 10 |
| 2 | CYBR | 10 |
| 1 | FB | 10 |
| 2 | IBM | 10 |
| 1 | JNJ | 10 |
| 2 | PFPT | 10 |
| 1 | F | 20 |
| 2 | FEYE | 20 |
| 1 | K | 20 |
| 2 | PANW | 20 |
Was produced using this query, where (I assume) you want the SEQ column calculated for you:
select
1 + mod(rn,2) Seq
, ticker
, industry
from (
select
ticker
, industry
, 1+ row_number() over (partition by industry
order by ticker) rn
from stocks
)
order by industry, rn
Please note this is a derivative of the earlier answer by Jon Heller, this derivative can be found online at http://sqlfiddle.com/#!4/088271/1