Query to group 5 records - sql

Question

I have table for eg "employee" with just one column "id". Say you have records from 1 through 1000.
Employee
------------
ID
------------
1
2
3
..
..
999
1000
Now I would like to write a query which gives the following results i.e. sort by ascending order and concatenate first 5 to 1 record, second 5 to 2 second, and so on. Any ideas how I can do this?
Here is the output I am looking to have.
1,2,3,4,5
6,7,8,9,10
11,12,13,14,15
...........
...........
996,997,998,999,1000

Answer 1

Use row_number and listagg functions, in this way:
SELECT listagg( id, ',' ) within group( order by group_no, id )
FROM (
select id,
trunc((row_number() over( order by id ) -1) / 5) as group_no
from employee
)
GROUP BY group_no
Working demo: http://sqlfiddle.com/#!4/ef526/10
| LISTAGG(ID,',')WITHINGROUP(ORDERBYGROUP_NO,ID) |
|------------------------------------------------|
| 1,2,3,4,5 |
| 6,7,8,9,10 |
| 11,12,13,14,15 |
| 16,17,18,19,20 |
| 21,22,23,24,25 |
| 26,27,28,29,30 |
| 31,32,33,34,35 |
| 36,37,38,39,40 |
| 41,42,43,44,45 |
| 46,47,48,49,50 |
| 51,52,53,54,55 |
| 56,57,58,59,60 |
| 61,62,63,64,65 |
| 66,67,68,69,70 |
| 71,72,73,74,75 |
| 76,77,78,79,80 |
| 81,82,83,84,85 |
| 86,87,88,89,90 |
| 91,92,93,94,95 |
| 96,97,98,99,100 |
| 101,102,103,104,105 |
| 106,107,108,109,110 |
| 111,112,113,114,115 |
| 116,117,118,119,120 |
| 121,122,123,124,125 |
| 126,127,128,129,130 |
| 131,132,133,134,135 |
| 136,137,138,139,140 |
| 141,142,143,144,145 |
| 146,147,148,149,150 |
| 151,152,153,154,155 |
| 156,157,158,159,160 |
| 161,162,163,164,165 |
| 166,167,168,169,170 |
| 171,172,173,174,175 |
| 176,177,178,179,180 |
| 181,182,183,184,185 |
| 186,187,188,189,190 |
| 191,192,193,194,195 |
| 196,197,198,199,200 |