I've got a unusual question.
The human resources needs to export an old DB to a new one.
And the guys managing the new DB wants one csv file with every dataset existing. I did a Relational database and now i find it difficult to write the select statement.

I did this:

FROM teilnehmer, personen, seminare, termine, kategorien, haeuser
WHERE teilnehmer.sid = seminare.sid  
AND teilnehmer.pid = personen.pid  
AND termine.sid = seminare.sid  
AND seminare.katid = kategorien.katid  
AND personen.hausid = haeuser.hausid
ORDER BY personen.pid

but i only get ~1500 entrys. I know thats to little, because when i look for a Name and all the workshops he/she did, i get much more than what is in this export.

I don't need the answer i would appreciate if someone could give me a little hint in how to get this done. Till yet i had only like one join for the data i'd needed to display but this confuses me.

1 Answer 1


My guess is you need to specify the type of join. You really want a "full outer join" which will not exclude records. A select where you join by keys will default to an inner join.

See https://stackoverflow.com/a/6188334/259538

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