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create table table1 (ab varchar(50), id int, suffix varchar(2), identifyno varchar(50))
insert into table1 values
('CON', 123, 'C', '12345-33344441-8'), ('CON2', 456, 'C1', '12345-33344441-8'),
('CON', 789, 'C', '12345-33344441-9'), ('CON2', 101, 'C1', '12345-33344441-9')
select * from table1
| ab | id | suffix | identifyno |
|---|---|---|---|
| CON | 123 | C | 12345-33344441-8 |
| CON2 | 456 | C1 | 12345-33344441-8 |
| CON | 789 | C | 12345-33344441-9 |
| CON2 | 101 | C1 | 12345-33344441-9 |
select t.ab,
t.id,
t.suffix,
t.identifyno,
( select string_agg(convert(varchar(50), t1.id), '-')
from table1 t1
where t1.identifyno = t.identifyno
) as merged_id
from table1 t
| ab | id | suffix | identifyno | merged_id |
|---|---|---|---|---|
| CON | 123 | C | 12345-33344441-8 | 123-456 |
| CON2 | 456 | C1 | 12345-33344441-8 | 123-456 |
| CON | 789 | C | 12345-33344441-9 | 789-101 |
| CON2 | 101 | C1 | 12345-33344441-9 | 789-101 |