Hi,
I am creating some graphs which I want to update into a database table.
The procedure I am following is:
1. create the graphs as a png/jpeg file.
2. Read that file as a binary vector
3. sqlUpdate
My code:
pngfile <- file(<filename>, "rb")
N <- 1e6
repeat{
pngfilecontents <- readBin(pngfile, what="raw", n=N)
if(length(pngfilecontents) == N) N <- 5 * N else break
}
close(pngfile)
#There is a table df_DemandPatternMaster in the database with primary
key DemandPatternID, with appropriate record in place with NULL value in
pngFile field.
update.query <- "update df_DemandPatternMaster set "
update.query <- paste( update.query, " pngFile = '",
serialize(pngfilecontents, NULL) , "' where DemandPatternID = ", , sep="")
d <- sqlQuery(connection, update.query)
I end up inserting only a byte of data. The reason it seems is that
paste sees the serialized vector and creates a vector with the prefix &
suffix text.
I have also tried passing the pngfile handle directly
pngfile <- file(<filename>, "rb")
update.query <- paste( update.query, " pngFile = '", pngfile, "' where
DemandPatternID = ", , sep="")
This also fails.
Please advise.
Regards
Baan
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