I am using the DBI package to connect to a SQL Server database and I am able to pull data from the table into R where the geom column is a geometry type according to SQL Server Management Studio.

But when the table is pulled into R, the geom column is shown as blob. This is how I am pulling the data into R:

data <- dbGetQuery(con,'SELECT * FROM "map_db"."city"."landcover"')

I would like to convert the blobs back to geometry (they are x,y coordinates in UTM). I don’t really need the coordinates per say but need to calculate areas for each polygon in R.

I tried the following thinking I could compute the area using SQL but it returned an error:

dbGetQuery(con,'SELECT * FROM "map_db"."city"."landcover".STArea();')

[Microsoft][ODBC SQL Server Driver][SQL Server]Remote table-valued function calls are not allowed.

I even tried st_as_sf but that gave me the following error:

data <- st_as_sf(dbGetQuery(con,'SELECT * FROM "map_db"."city"."landcover"'))

Error in st_sf(x, …, agr = agr, sf_column_name = sf_column_name):
no simple features geometry column present

Unfortunately, I am not able to provide access to the database so I understand this may make it harder to help my exact case but any suggestions would be welcomed.