z35 (events) table doesn't match z36h (loan history) table

• Article Type: General
• Product: Aleph
• Product Version: 18.01

Description:
We are trying to create some reports to find out how many times items in storage have circulated within the last five years. We are obtaining the counts from the z35 table, counting simple loans, offline loans, and browses. We are finding many cases where according to the z35 table there have been 6 or 7 loans, but when you look at the loans in the item history of the circulation client, the number of loans is 0. Where is the data for item history/loans coming from? Why would it not match up with the z35 events table?

Resolution:
The z35 loan record (event_type 5x) (or, for an In-house use transaction, event type 80 or 82) is written when the loan occurs.

The z36h loan history record is written only when the item is returned. If the item is on long-term loan, this could explain it. To get a complete picture of loans, you need to look at both the z36h *and* the z36.