Re: SQL join, limit to one row per employee

Hi Kerwin,

I, for similar cases, usually use ROW_NUMBER() OVER() in a subselect and
then select row one.


Although the LIMIT clause doesn't seem like a bad idea to me.

Javier Mora

El mar, 13 may 2025 a las 16:33, Daniel Gross (<daniel@xxxxxxxx>) escribió:

Hi Kerwin,

Am 13.05.2025 um 16:24 schrieb K Crawford <kscx3ksc@xxxxxxxxx>:

I have an SQL doing an inner join between two tables.
The results have two rows for some employees, due to one table having two
'active' rows for that employee.
How can I write my SQL to only have one row for that employee?
This is my SQL.
SELECT em.*
FROM qs36f.v@ep_0 as ep
inner join qs36f.v@em_0 as em
on em.client = ep.client and em.rnum = ep.rnum and
em.enum = ep.employee#
[snip]

This here should work:

select em.*
from qs36f.v@ep_0 as ep
join lateral (
select *
from qs36f.v@em_0
where em.client = ep.client and em.rnum = ep.rnum and em.enum =
ep.employee#
limit 1
) as em on true
where ...


I'm was thinking that the "em" file was the one with the two active
records - if not, the same technique works also in the FROM clause.

HTH and kind regards,
Daniel
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