SQL Inner Join and nearest row to date - sql

Question

I dont't get it. I changed some of the code. In the WPLEVENT Table are a lot of Events per person. In the Persab-Table are the Persons with their History. Now I need the from the Persab Table just that row wich matches the persab.gltab Date nearest to the WPLEVENT.vdat Date. So all rows from the WPLEVENT, but just the one matching row from the PERSAB-Table.
SELECT
persab.name,
persab.vorname,
vdat,
eventstart,
persab.rc1,
persab.rc2
FROM wplevent
INNER JOIN
persab ON WPLEVENT.PersID = persab.PRIMKEY
INNER JOIN
(SELECT TOP 1 persab.rc1
FROM PERSAB
WHERE persab.gltab <= getdate() --/ Should be wplevent.vdat instead of getdate()
) NewTable ON wplevent.persid = persab.primkey
WHERE
persid ='100458'
ORDER BY vdat DESC

Answer 1

Need to use the MAX() function with the proper syntax by supplying an expression like MAX(persab.rc1). Also need to use GROUP BY for the second column rc2 in the subquery (although it looks like you do not need it). Finally you are missing the ON clause for the final INNER JOIN. I can update the answer to fix the query if you provide that information.
SELECT
Z1PERS.NAME
, Z1PERS.VORNAME
, WPLEVENT.VDat
, WPLEVENT.EventStart
, WPLEVENT.EventStop
, WPLEVENT.PEPGROUP
, Z1SGRP.TXXT
, PERSAB.GLTAB
, Z1PERS.PRIMKEY AS Expr1
, PERSAB.PRIMKEY
FROM
Z1PERS
INNER JOIN
WPLEVENT ON Z1PERS.PRIMKEY = WPLEVENT.PersID
INNER JOIN
Z1SGRP ON WPLEVENT.PEPGROUP = Z1SGRP.GRUPPE
INNER JOIN
(
SELECT MAX(Persab.rc1) --Fixed MAX expression
, persab.rc2
FROM
persab
GROUP BY
persab.rc2 --Need to group on rc2 if you want that column in the query otherwise remove this AND the rc2 column from select list
WHERE
WPLEVENT.PersID = PERSAB.PRIMKEY
AND WPLEVENT.VDat <= PERSAB.GLTAB
) --Missing ON clause for the INNER JOIN here
WHERE z1pers.vorname = 'henning'