Presumably this about RMySQL, and by 'database' you mean a MySQL
database,
not e.g. a .rdb file?
R-sig-db would be a better list, but I think this is one of many aspects
of the DBI package that that not been updated to match improvements in R.
On Thu, 25 Sep 2008, Christian Ruckert wrote:
> Someone solved the problem of saving R-objects to a database?
>
> These are the two varaints I've tried so far without success:
>
> 1)
> ser = rawToChar(serialize(obj, NULL, ascii=TRUE))
> dbSendQuery(link, paste("insert into table values(1,
'",ser,"')",sep=''))
This will not work, because rawToChar can give embedded nuls.
> The field to save the object in the MySQL Database is of type text.
>
> unser = dbGetQuery(link,"select * from table where id=1")
> Warning message:
> In mysqlFetch(res, n, ...) :
> RS-DBI driver warning: (internal error: row 0 field 1 truncated)
>
>
> 2)
> ser = serialize(obj, NULL)
> dbSendQuery(link, paste("insert into table values(1,
'",ser,"')",sep=''))
>
> The field to save the object in the MySQL Database is of type blob.
>
> result = dbGetQuery(link,"select * from table where id=1")
>
> unser = unserialize(result[1,"object_column"], NULL)
DBI needs to convert blobs to raw not character.
> Error in unserialize(result[1, "object_column"], NULL) : unknown
input format
> In addition: Warning message:
> In unserialize(result[1, "object_column"], NULL) :
> unserialize()from a character string is deprecated and will be withdrawn
in
> R 2.8.0
>
>
> Any suggestion is welcome.
>
> Best,
> Christian
--
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
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