Adding table from Postgis

Question

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:

CREATE TABLE everest
(
 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 .

• Nathan W: How are you trying to open the raster layer?

Answer 1

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:

CREATE TABLE everest
(
 rid serial PRIMARY KEY,
 rast raster,
 filename text
)

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