Is it possible to combine the values ​​of a string field through a delimiter in a group by sql query?

Question

SQL

There is a query that collects data from three tables into four fields to add them to the fourth, but in the fourth three fields are key and a non-uniqueness error occurs. It is required to get one from several lines, in which unique keys will remain as they are, and in the fourth text field, the values ​​of all lines will be combined through a separator.

Answer 1

well, you group by key fields, non-key - group_concat(t.field)

Answer 2

implode('|'...), json??