MS Access: Calculate date interval between records in a table

[aneinander]

I'm beginner and getting following error message, please help.
The table contains transaction date, account number, branch, etc. And need to show previous transaction date or next transaction date of the account number next to each record,
then calculate date interval.
Thank you in advance,
Sean,
----error message----
"You tried to execute a query that does not include the specified expression 'NEXTDATE' as part of an aggregate function.
----access query----
SELECT A.TRDAT7, B.TRDAT7 AS NEXTDATE, DateDiff("d",A.TRDAT7,NEXTDATE) AS dateinterval, A.BRANCH, A.TRACCT
FROM LNREDFLAG AS A LEFT JOIN LNREDFLAG AS B ON (A.TRACCT=B.TRACCT) AND (A.TRDAT7<B.TRDAT7)
GROUP BY A.TRDAT7, A.BRANCH, A.TRACCT;

[PianoMan64]

I'm beginner and getting following error message, please help.
The table contains transaction date, account number, branch, etc. And need to show previous transaction date or next transaction date of the account number next to each record,
then calculate date interval.
Thank you in advance,
Sean,
----error message----
"You tried to execute a query that does not include the specified expression 'NEXTDATE' as part of an aggregate function.
----access query----
SELECT A.TRDAT7, B.TRDAT7 AS NEXTDATE, DateDiff("d",A.TRDAT7,NEXTDATE) AS dateinterval, A.BRANCH, A.TRACCT
FROM LNREDFLAG AS A LEFT JOIN LNREDFLAG AS B ON (A.TRACCT=B.TRACCT) AND (A.TRDAT7<B.TRDAT7)
GROUP BY A.TRDAT7, A.BRANCH, A.TRACCT;

As long as the dates are different, then you would not use NextDate in your DateDiff Function, you would simply place B.TRDAT7 in place of NEXTDATE

Let me know if that workes.

Thanks,

Joe P.