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swcarpentry / DEPRECATED-bc

DEPRECATED: This repository is now frozen - please see individual lesson repositories.
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Made two small changes to the SQL NULL lesson. #884

Closed timtomch closed 9 years ago

timtomch commented 9 years ago

There was a small mistake in the description of the penultimate example: the text said that we wanted to exclude measurements taken by Dyer, whereas the SQL query was excluding measurements taken by Lake. This was corrected.

Also, I added a brief paragraph on the effects of NULL values on aggregation functions, referring the next section and slightly modified a line that was saying "null values cause headaches wherever they appear" to say that "null values CAN cause headaches…" Both changes to try to underline that NULL values are not a bad thing. They require extra caution, but are helpful.

Changes were made to the iPython notebook (05-null.ipynb), which was compiled to make a new Markdown file (05-null.md).

This is my first pull request to the repository, and part of my Software Carpentry instructor training, so apologies if I'm doing it wrong :)

rgaiacs commented 9 years ago

@timtomch Thanks for this pull request. Could you reopen it at https://github.com/swcarpentry/sql-novice-survey? After do it could you also close this pull request?

timtomch commented 9 years ago

Done.