Hello
create table t1(d date, n integer);
postgres=# insert into t1 select '2001-01-01', 1 from generate_series(1,3);
INSERT 0 3
but
postgres=# insert into t1 select distinct '2001-01-01', 1 from
generate_series(1,3);
ERROR: column "d" is of type date but expression is of type text
LINE 1: insert into t1 select distinct '2001-01-01', 1 from generate... ^
HINT: You will need to rewrite or cast the expression.
Regards
Pavel Stehule