Обсуждение: Not seeing script error

The script:

select p.person_nbr, p.fname, p.lname, p.job_title, p.direct_phone, p.email,
        c.company_nbr, c.company_name, c.industry
from people as p
inner join companies as c on p.company_nbr = c.company_nbr
where p.email is not null and
industry = 'Chemicals' or
industry = 'Energy' or
industry = 'Food processor' or
industry = 'Manufacturing' or
industry = 'Maritime' or
industry = 'Transportation' or
industry = 'Wood products'
group by p.person_nbr, c.company_nbr
order by p.person_nbr;

The where condition, `p.email is not null' is not working; the results
include rows where email is null while all other columns are okay.

I had that condition following the industry conditions but that makes no
difference.

What have I missed?

TIA,

Rich

Rich Shepard <rshepard@appl-ecosys.com> writes:
> The script:
> select p.person_nbr, p.fname, p.lname, p.job_title, p.direct_phone, p.email,
>         c.company_nbr, c.company_name, c.industry
> from people as p
> inner join companies as c on p.company_nbr = c.company_nbr
> where p.email is not null and
> industry = 'Chemicals' or
> industry = 'Energy' or
> industry = 'Food processor' or
> industry = 'Manufacturing' or
> industry = 'Maritime' or
> industry = 'Transportation' or
> industry = 'Wood products'
> group by p.person_nbr, c.company_nbr
> order by p.person_nbr;

> The where condition, `p.email is not null' is not working; the results
> include rows where email is null while all other columns are okay.

> I had that condition following the industry conditions but that makes no
> difference.

> What have I missed?

AND binds more tightly than OR.  I think you meant

where p.email is not null and
(industry = 'Chemicals' or
industry = 'Energy' or
industry = 'Food processor' or
industry = 'Manufacturing' or
industry = 'Maritime' or
industry = 'Transportation' or
industry = 'Wood products')

BTW, using IN might make this more compact.

            regards, tom lane

On Thu, 8 Jan 2026, Tom Lane wrote:

> AND binds more tightly than OR.  I think you meant
> where p.email is not null and
> (industry = 'Chemicals' or
> industry = 'Energy' or
> industry = 'Food processor' or
> industry = 'Manufacturing' or
> industry = 'Maritime' or
> industry = 'Transportation' or
> industry = 'Wood products')

Tom,

While I'm aware that AND binds tigher than OR, I totally missed the need to
package all industry names within parentheses.

> BTW, using IN might make this more compact.

And, it enforces industry types to be in parentheses.

Thanks very much,

Rich