Re: Concatenation through SQL

Pavel Stehule wrote:

>> SELECT
>> appointments.name AS appointment,
>> (SELECT COUNT(*) FROM employees AS e where e.appointment_id =
>> appointments.id) AS num_employees,
>> (SELECT array_to_string(array_accum(name),', ') FROM employees AS e
>> WHERE e.appointment_id = appointments.id) AS employees FROM
>> appointments ---------------------------------------
>>
>
> hello,
>
> one note: you can merge your two subselect into one. It's unimportant
> on 100 rows, but it's can be important on thousands rows.
>
> nice a day
> Pavel

Hi Pavel,

Since subselects must return one single column, is that what you are
talking about? I have just modified the code you have posted before.

---------------------------
SELECT
name AS appointment,
num_employees,
employees

FROM
(
SELECT
appointment_id,
COUNT(*) AS num_employees,
(SELECT array_to_string(array_accum(name),', ') FROM employees WHERE
e.appointment_id = appointment_id) AS employees
FROM employees e
GROUP BY appointment_id
)s

JOIN appointments a on a.id = s.appointment_id;
---------------------------

Philippe