[SQL] Create Datefield from 3 fields

[Andreas Forø Tollefsen]

Hi.

I am trying to create a datefield using YEAR, MONTH and DAY fields of type
integer.
I tried this query, but it did not give good results:
select to_date(gwsyear::text || gwsmonth::text || gwsday::text,
'YYYY-MM-DD') FROM cshapes
"1966526-01-01"
"7991903-12-13"
"1962831-01-01"
"194611-01-01"
"196211-01-01"

Any ideas on how to do this?