This workflow might satisfy your requirement, although I'd further research the continued use of the Raster column and perhaps determine if the Attachments model is a more appropriate option for the final repository.
Your first task is to retrieve the contents of the Raster column from the source Feature Class. If you will ultimately want to populate the destination with Attachments then you will need to establish a unique value for each feature and name the output image with that value. Here I have an "Imgs" column representing the Raster column and "DBKEY" column that is simple a text type that has 5 character values unique to each feature.
def writeRasFldContents():
#set the env workspace, otherwise it will write results to C:\users... dir
arcpy.env.workspace = r'H:\saveFolder'
arcpy.env.overwriteOutput = True
#specify an output folder to write out the Raster column images
output_path = r'H:\saveFolder'
os.chdir(output_path)
#input FeatureClass with the Raster column you wish to write out to a blob field
fc = r'H:\Documents\ArcGIS\Default.gdb\XY01TEST'
#write the images from the raster column, skipping any nulls or else it will error
with arcpy.da.SearchCursor(fc, ("Imgs", "DBKEY"), skip_nulls=True) as cursor:
for row in cursor:
filename = "{0}.tif".format(row[1])
row[0].save(filename)
print filename
del row
del filenameNow that we have a file folder of output images in a folder and each relates back to each feature, you can now go thru the process to setup Attachments on the SDE feature class (just use the Geoprocessing tools to perform this).
if you simply want to add a blob field onto the source feature class and populate it with the Raster column, these two additional def's will accomplish that:
def writeBlobs():
fc = r'H:\Documents\ArcGIS\Default.gdb\XY01TEST'
input_path = r'H:\saveFolder'
full_file_paths = get_filepaths(input_path)
for f in full_file_paths:
if f.endswith(".tif"):
imgname = os.path.basename(f)
dbkey = os.path.splitext(imgname)[0]
expr = "DBKEY= '" + dbkey + "'"
print expr
myfile = open(f, 'rb').read()
#Imgs2 is the new blob column to populate the imgs
with arcpy.da.UpdateCursor(fc, ['Imgs2'], expr) as ucur:
for urow in ucur:
urow[0] = myfile
ucur.updateRow(urow)
def get_filepaths(directory):
file_paths = [] # List which will store all of the full filepaths.
# Walk the tree.
for root, directories, files in os.walk(directory):
for filename in files:
# Join the two strings in order to form the full filepath.
filepath = os.path.join(root, filename)
file_paths.append(filepath) # Add it to the list.
return file_paths Finally if you want to read the blobs to validate:
def readBlobs():
#to check if the blob column was updated with the content of the raster column
fc = r'H:\Documents\ArcGIS\Default.gdb\XY01TEST'
with arcpy.da.SearchCursor(fc, ['Imgs2', 'DBKEY'], skip_nulls=True) as cursor:
for row in cursor:
binaryRep = row[0]
fileName = row[1]
print fileName
#save the content of the raster field to a new folder
open(r'H:\saveFolder2' + os.sep + fileName, 'wb').write(binaryRep.tobytes())
del row
del binaryRep
del fileName
