sql - Remove subsequent duplicate string in a column of table -

i have table named event

id     event_sequnce 1      a->c->b->b->b->c->b 2      d->d->a->d->c->a->a->c

i want remove subsequent duplicate letter column event_sequnce

so output table be

id   event_sequnce 1    a->c->b->c->b 2    d->a->d->c->a->c

how write query achieve this?

you have use regex it:

select regexp_replace('d->d->a->d->c->a->a->c', '(\w\-\>)\1+', '\1', 'g');

update version

select regexp_replace(regexp_replace(textcat('d->d->a->d->c->a->a->c->c', '->'), '(\w\-\>)\1+', '\1', 'g'), '\-\>$', '');

Prevent