dynamic postgres inside shell script not working

PG_CMD="psql -d $DB_NAME -U $DB_USER -c "
PG_CMD_TP="psql -d $DB_NAME -U $DB_USER -t -P format=unaligned -c "
abc()
{
 $PG_CMD " 
        DO \$$

           BEGIN
                   select * from customer;
          END; 
        \$$";
}
*******MAIN***
abc

I want to print result of query on command line as well as I want to send it to excel file.I was expecting result of query on command line.But I am not getting anything.Thanks in advance.