[Koha] Barcode as a link report

[Mark Alexander]

Excerpts from muirunyeri's message of 2020-05-19 11:10:33 +0300:
> However if anybody would help me understand why I get an error (biblionumber is ambiguous) after adding any field from biblio table I'd be really grateful. This after correctly adding a left join for the biblios table using biblionumber on itemnumber in items.

It would help if you could post your entire query.  But my guess is
that the ambiguity is the result of joining two tables that have
fields with the same name.  The items and biblio tables both have a
field called biblionumber.  So in your query, you have to fix the
ambiguity by using the table name as a prefix: e.g.,
items.biblionumber or biblio.biblionumber .