echo "
create table t (v int not null);
insert into t values (1) ;
insert into t values (10) ;
insert into t values (12) ;
insert into t values (0) ;
select 10/v from t;
" | psql -a          #  -a => echo all input from script

-- yields:

create table t (v int not null);
CREATE TABLE
insert into t values (1) ;
INSERT 0 1
insert into t values (10) ;
INSERT 0 1
insert into t values (12) ;
INSERT 0 1
insert into t values (0) ;
INSERT 0 1
select 10/v from t;
ERROR:  division by zero