SQL update one single row table with data from another - sql

Question

I have two tables. The first one with all movements in twelve months and the second one with claims registered in the same period of time. When I run the following query from the first table I've got 10 records. Of course, there are other records with a different number of movements (e.g.: 7, 23, 2 movements):
select t.cod_suc
,t.cod_ramo_comercial
,t.Poliza
,t.Item
,t.id_pv
from temp_portafolio_personal_accidents as t
where t.cod_suc = 2
and t.cod_ramo_comercial = 46
and t.Poliza = 50283
and t.Item = 1
and t.id_pv = 788383;
With the second query, for the second table, I have the following results:
select c.cod_suc
,c.cod_ramo_comercial
,c.[No. Policy]
,c.Item
,c.[ID Incident]
,max(c.id_pv) as id_pv
,count(distinct [No. Incident]) as 'Conteo R12'
from #claims as c
where c.[ID Incident] = 343632
group by c.cod_suc
,c.cod_ramo_comercial
,c.[No. Policy]
,c.Item
,c.[ID Incident];
Now, I need to update the first table but only one record. I'm using the following query, but all records are being updated. When I sum results I have 10 but is just one claim, as the second query shows.
update p
set [No. Siniestros R12] = b.[Conteo R12]
from temp_portafolio_personal_accidents p
left join
(select c.cod_suc
,c.cod_ramo_comercial
,c.[No. Policy]
,c.Item
,c.[ID Incident]
,max(c.id_pv) as id_pv
,count(distinct [No. Incident]) as 'Conteo R12'
from
#claims as c
where c.[ID Incident] = 343632
group by c.cod_suc
,c.cod_ramo_comercial
,c.[No. Policy]
,c.Item
,c.[ID Incident]
) b
on p.id_pv = b.id_pv
and p.cod_suc = b.cod_suc
and p.cod_ramo_comercial = b.cod_ramo_comercial
and p.Poliza = b.[No. Policy]
and p.Item = b.Item
where p.id_pv = 788383;

Answer 1

You can use a CTE with a ROW_NUMBER() function to do this. Simple example:
DECLARE #TABLE AS TABLE (Testing INT, Testing2 VARCHAR(55), Testing3 BIT);
INSERT INTO #TABLE VALUES (1, '1', 1);
INSERT INTO #TABLE VALUES (1, '1', 1);
INSERT INTO #TABLE VALUES (1, '1', 1);
INSERT INTO #TABLE VALUES (1, '1', 1);
INSERT INTO #TABLE VALUES (1, '1', 1);
INSERT INTO #TABLE VALUES (1, '1', 1);
INSERT INTO #TABLE VALUES (1, '1', 1);
INSERT INTO #TABLE VALUES (1, '1', 1);
WITH CTE AS
(
SELECT
ROW_NUMBER() OVER (ORDER BY Testing) AS RowID
,Testing
,Testing2
,Testing3
FROM #TABLE
)
UPDATE CTE
SET Testing = 2, Testing2 = '2', Testing3 = 0
WHERE RowID = 1
;
SELECT * FROM #TABLE
;