parse hl7 with regex

Question

I have the following hl7 message: MSH|^~\\&|EPIC|SMHRMC|JCAPS|QHN|20170626165726|EDILABIH|ORU^R01^LAB|00004841|P|2.3||||||||| PID|1||W00xxxxx^^^SMHRMC||mouse^Mickey^E||19860905|F||1|2601 somestreet AVE NO 8^^City^ST^zip^USA^^^county|MESA|(970)xxx-xxxx^P^PH|||Single||175375903|xxxxxxx||last^first^^|NON-HISPANIC|||||||||| PV1|1|I|MNEU^908^A^^R^^^^^^||||9999999^pcp^pcp^LYNNE^^^^^NPI^^^^NPI~999999999^last^first^LEE^^^^^NPI^^^^NPI||||||||||00000000^last^first^LYNNE^^^^^NPI^^^^NPI||000000603|CAID||||||||||||||||||||||||20170626000000 MSH|^~\\&|EPIC|SMHRMC|JCAPS|QHN|20170626165726|EDILABIH|ORU^R01^LAB|00004841|P|2.3||||||||| PID|1||W00xxxxx^^^SMHRMC||mouse^Mickey^E||19860905|F||1|2601 somestreet AVE NO 8^^City^ST^zip^USA^^^county|MESA|(970)xxx-xxxx^P^PH|||Single||175375903|xxxxxxx||last^first^^|NON-HISPANIC|||||||||| PV1|1|I|MNEU^908^A^^R^^^^^^||||9999999^pcp^pcp^LYNNE^^^^^NPI^^^^NPI~999999999^last^first^LEE^^^^^NPI^^^^NPI||||||||||00000000^last^first^LYNNE^^^^^NPI^^^^NPI||000000603|CAID||||||||||||||||||||||||20170626000000

Hl7 is hard to extract with regex however I have an field that is always in the same location and feel that might be easier. I need to pull the encounter number which is the 'W00xxxxx' in the stream above. It is always in the 3rd pipe delimited section of the PID and stops at the ^.

Currently I have: select substring(column from 'PID\\|[1]\\|\\|(.)\\^') but this is not working. However when I use select substring(column from 'PV1\\|[1]\\|(.)\\|') it will pull the 'I'. I can't see the big differences in my regex to know why this isn't working. Thanks.

Answer 1

这个怎么样：

PID\|[1]\|\|(.+?)\^

Answer 2

You can't reliably parse HL7 V2.x messages using regex because the encoding characters may change in MSH-1 and MSH-2. Whatever language you're using there's probably already an HL7 parsing library you can use instead.