CONCAT_WS
Concatenate a series of strings, using the first argument as a separator between the strings. This function also accepts values that are not character strings, such as integers and timestamps.
NULL
arguments are ignored.
CONCAT_WS(separator, string [, string [ , … ] ])
For example, combine two character columns and separate them with a hyphen (-):
premdb=# SELECT CONCAT_WS('-',nickname,city) FROM team LIMIT 5;
concat_ws
---------------------
Gunners-London
Villains-Birmingham
Tykes-Barnsley
Blues-Birmingham
Rovers-Blackburn
(5 rows)
Combine two integer columns and separate them with a colon:
premdb=# select concat_ws(':',htid,atid) from team order by htid;
concat_ws
-----------
2:51
3:52
4:53
5:54
6:55
7:56
...