1 Fix For "Blank" (Empty String) TCN Source
3 Previously, it was possible for sparsely-populated MARC records to be
4 saved with a TCN Source of '' (the "empty string"), which caused the
5 901 $b subfield to be void of data, causing errors when exporting
6 MARC records to such third-party programs as Zotero.
8 A site that has been running without this patch for a long time might want to
9 check how many bib records they have with an empty tcn_source:
11 SELECT COUNT(*) FROM biblio.record_entry WHERE deleted IS FALSE AND tcn_source = '';
13 Sites can fix the problem by issuing UPDATE statements to set the 901$b to a value
14 like 'AUTOGEN' or 'Unknown'. They should probably do it per-record, however, to
15 avoid locking the table in a huge commit.