While trying to import a table containing raster data in QGIS , Raster column is not being imported ... I am getting following messages:

  1. Database connection was successful , but the accessible tables could not be determined.

  2. The view 'public.raster_columns' has no column suitable for use as a unique key. Quantum GIS requires that the view has a column that can be used as a unique key. Such a column should be derived from a table column of type int4 and be a primary key, have a unique constraint on it, or be a PostgreSQL oid column. To improve performance the column should also be indexed.

Please help.

Table Used:

  rid serial NOT NULL,
  rast raster,
  filename text,

After adding primary key constraint also , I am getting same error message. I use raster2pgsql command to create a sql file corresponding to the raster tif file. And thereafter pgadmin to create table in postgis from the sql file , Here , rid is primary key and of type serial .

  • 1
    How are you trying to open the raster layer? – Nathan W Jun 12 '12 at 13:35

Not sure about the first error, but it sounds like you need a primary key column. Looks like that's what you intended 'rid' to be, since it's a serial field, but you still need to explicitly state that it's the PK:

    rid serial PRIMARY KEY,
    rast raster,
    filename text

Note that using PRIMARY KEY implies both UNIQUE and NOT NULL.

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