[R] Numerical print format and loading with RMySQL
Nathan Johnson
njohnson at ebi.ac.uk
Tue Jun 13 16:57:02 CEST 2006
Hi
I'm new to R and have been resisting posting to the list thus far,
but I think I've exhausted my work around options.
I'm having a few problems with RMySQL and/or it's underlying packages.
I'm doing a very simple vsn transformation on large datasets, using
RMySQL to retrieve the data for a DB.
My first problem was that I could not get the RMySQL package to write
back to my DB using the dbWriteTable method.
I constructed a data frame with columns corresponding to the table
fields, and tried with and without a null column for the auto-
increment internal id column. I also tried renaming all the column
names to match those of the table fields. All of my attempts
resulted in a long wait and "TRUE" being printed to the terminal,
which I though was quite promising, however, on inspection of the DB,
I found nothing had been written. So my first question are:
Is it necessary to provide field names of the table, or will correct
column order suffice?
For tables with an internal auto-increment DBID field, is it
necessary to provide a null column of the correct length?
To get around this I decided to use the write.table function and then
import via my controlling perl script. This works fine apart from
one problem, numbers >-100000 get printed as exponents, which then
causes subsequent imports to miss these records. So my second and
rather simple question is:
Is there a setting(options?) which will force full numerical printing?
Thanks in advance
Nath
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