Hello everyone, The SQL query to get the frequency for different serials was given on the KOHA SQL Library as : SELECT IF ( LOCATE('<datafield tag="310"', biblio_metadata.metadata) = 0 OR LOCATE('<subfield code="a">', biblio_metadata.metadata, LOCATE('<datafield tag="310"', biblio_metadata.metadata)) = 0 OR LOCATE('<subfield code="a">', biblio_metadata.metadata, LOCATE('<datafield tag="310"', biblio_metadata.metadata)) > LOCATE('</datafield>', biblio_metadata.metadata, LOCATE('<datafield tag="310"', biblio_metadata.metadata)), '', SUBSTRING( biblio_metadata.metadata, LOCATE('<subfield code="a">', biblio_metadata.metadata, LOCATE('<datafield tag="310"', biblio_metadata.metadata)) + 19, LOCATE('</subfield>', biblio_metadata.metadata, LOCATE('<subfield code="a">', biblio_metadata.metadata, LOCATE('<datafield tag="310"', biblio_metadata.metadata)) + 19) - (LOCATE('<subfield code="a">',biblio_metadata.metadata, LOCATE('<datafield tag="310"', biblio_metadata.metadata)) + 19) ) ) AS FREQUENCY When I run this query, it gives the output like 54/yr for some journals, which is correct, but for some, it returns something like 'M', '0', 'FN', 'SM', '#N/A', etc. Can someone please help me understand what should be the correct SQL query? Thanks in advance Regards *Raghav Arora* Sophomore, M.Sc (Hons) Chemistry BE Electrical and Electronics Engineering Contact : (+91) 9897597761, 8474975691 Personal Email <raghavarora999@yahoo.in> | University Email <f20171016@pilani.bits-pilani.ac.in> LinkedIn <https://www.linkedin.com/in/raghav-arora-9820a648/> | GitHub <https://github.com/RAraghavarora/> ▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄ *Birla Institute of Technology and Science, Pilani* Pilani campus, Rajasthan-333031