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Re: Database aliases
- Subject: Re: Database aliases
- From: Chris Travers <..hidden..>
- Date: Mon, 21 Nov 2011 16:35:52 -0800
A couple quick thoughts:
1) In well written SQL queries your aliases are in one place for easy
checking. It's a lot easier even in a 100 line query to review the
from clause than it is when you are writing the query to be looking up
acceptable alias names in a spreadsheet or a long text file (we are
approaching 200 relations and some queries use short inline views).
2) The SQL queries in the old code are not well written. They
typically are created by concatenation of text strings, and it isn't
always as obvious what all is in the query as we'd like.
I think the issue of acceptable aliases is beside the point. The old
code has database structure changes retrofitted onto it which raises
problems and it is hard enough to read that trying to retrofit a
system of acceptable list of aliases there is likely to be a bug
If we are to look at a coding convention in this area, I would suggest
we focus on new code and simply adopt a rule which states that inline
views should be discouraged for inline views of any complexity, since
that's the worst SQL debugging I have ever had to do has involved
that. I would note that the new code generally requires that most
queries are well written as a structural matter.
For the old code, I think the way to think about it is "it's on life
support until a replacement arrives."