Question

I’m working with oracle legacy DB and need to read and write binary data (png images, and and MDL Molfiles).
Django’s inspectdb command generated text fields for these columns, saying that’s only a guess.
Now, when I’m trying to retrieve a value from this class fields i get:
DjangoUnicodeDecodeError: ‘utf8’ codec can’t decode byte 0x89 in position 0: invalid start byte.
error.

Is there any way to read and write these columns?
Any help would be appreciated.

Answer 1

class BlobField(models.TextField):
    description = "Stores raw binary data"

    __metaclass__ = models.SubfieldBase

    def __init__(self, *args, **kwds):
        kwds = _adjust_keywords(kwds)
        super(BlobField, self).__init__(*args, **kwds)

    def get_internal_type(self):
        return "BlobField"

    def get_db_prep_value(self, value, connection=None, prepared=False):
        return value

    def to_python(self, value):
        return Blob(value)