[OGDev] Database constraints

[IvorW]

Answering a question on Perlmonks: http://perlmonks.org/?node_id=601407
has set me thinking about our geodata fields, in particular our lat +
long. To be valid, these must be numeric; in fact the Google Maps code
will b0rk if there's garbage in there. This made me wonder if the check
could be done DB side, in the form of a constraint, or possibly as a
trigger to calculate the X and Y.

... Which made me think about the wider issue of data validation. I know
MySQL isn't brilliant in this area, but I'm no up to speed with Pg
enough to know what's on offer. I am aware of how commercial databases
like Oracle and Sybase do it; that's my bread and butter.

If we had more validation checks in, either server side or DB side, we
could probably block more spam, as the 'bots tend to put rubbish and
URLs into many of our fields.

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