问题
I'd like to save a plot image directly to the database.
Is the best way in R to do this:
- Write the plot image (png) to the filesystem
- Read the file that was written
- Send the file to the database via query (RODBC)
Ideally I'd like to combine steps 1 and 2 above by simply write the png image to a binary connection. Does R support this?
回答1:
No, the graphics devices are file-based, so your steps 1-3 are correct. You need a fourth to unlink the temporary file but that is about it.
回答2:
If you use either lattice or ggplot, you can save the plot object (rather than the image itself) to the database (although I don't know if that meets your requirement). The benefit of that approach is that you can easily recreate/alter the image.
回答3:
Instead of writing to a regular file, could you write it to a FIFO that would in turn store it in the DB? Will graphics devices write to a FIFO if it's created externally?
来源：https://stackoverflow.com/questions/2045837/how-to-save-r-plot-image-to-database