[mapguide-users] Help required following up on a FDO PostgreSQL provider bug

[Jackie Ng]

Unfortunately, I still could not get this "class not found" to trigger with
the instructions given.

Nevertheless I looked at the code in question and can see how the way the
query is currently constructed would be incorrect in certain cases.

So as much as it pains me, I have made a *theoretical* fix and will have to
ask you to confirm if this issue is resolved by it.

The code patch in question is here:

https://trac.osgeo.org/fdo/attachment/ticket/1003/postgis-matview.patch

A compiled PostGIS provider with these code changes can be downloaded here:

https://download.osgeo.org/mapguide/releases/4.0.0/Beta3/Patches/PostgreSQLProvider.zip

Download and overwrite the existing PostgreSQLProvider.dll in your existing
MG 4.0 Beta 3 install.

Please do let me know if this resolves your issue as soon as possible.
Thanks.

- Jackie

You wrote:

Hi,

I think that error occurs only when you are viewing data

I think that error occurs only when you are viewing data as layer. Here's

steps for replicating that.

1. Start

1. Start with empty database with postgis extension created.

2. Create normal view with this command:

CREATE VIEW public.v_test

 AS

 WITH point_series AS (

         SELECT generate_series('-20'::integer::numeric, 20::numeric, 0.5)

AS point_values

        )

 SELECT row_number() OVER () AS id,

    st_setsrid(st_point(point_values::double precision,

point_values::double precision), 4326) AS geom

   FROM point_series a;

3. Create database connection in Mapguide and layer from view

3. Create database connection in Mapguide and layer from view above and and

that to Map.

4. Browse Map and everything is fine.

5. Create materialized view to database. It should work with previous

examples too but you can also create materialized view with geometry column

in it.

CREATE MATERIALIZED VIEW public.mv_test2

AS

 WITH point_series AS (

         SELECT generate_series('-20'::integer::numeric, 20::numeric, 0.5)

AS point_values

        )

 SELECT row_number() OVER () AS id,

    st_setsrid(st_point(point_values::double precision,

point_values::double precision), 4326) AS geom

   FROM point_series a;

6. Refresh database datasource in Mapguide so it will get info about new

materialized view.

7. Browse Map for awhile. Layer will be lost and visible again and error

log will have rows showing error  Class 'public:v_test' not found

8. Delete materialized view from database, refresh datasource and layer

will work again when Browsing map.

If you

If you run query shown in ticket with correct parameters it will return

only table or normal view with same schema and name as in parameters and

all materialized views. If you add these conditions to where part of second

select after union query will return only wanted rows. Values should be the

same as placed to first select.

AND ns.nspname='public' AND c.relname='v_test'

SELECT  t.table_schema  || '.' || t.table_name AS name,

 lower(t.table_type) AS type,  convert_to(t.table_schema,'UTF8') as

collate_schema_name,  convert_to(t.table_name,'UTF8') as collate_table_name

FROM information_schema.tables AS t

WHERE t.table_schema not in ( 'information_schema' ,'pg_catalog')  and  (

(t.table_schema = 'public' and t.table_name = 'v_test') ) AND t.table_type

IN ('BASE TABLE','VIEW')  AND t.table_name not in ( 'geometry_columns',

'geography_columns','spatial_ref_sys', 'raster_columns', 'raster_overviews')

UNION

SELECT ns.nspname || '.' || c.relname AS name,  'view' AS type,

 convert_to(ns.nspname,'UTF8') AS collate_schema_name,

 convert_to(c.relname,'UTF8') AS collate_table_name

FROM pg_class AS c  JOIN pg_namespace ns ON c.relnamespace = ns.oid

WHERE c.relkind = 'm' AND ns.nspname='public' AND c.relname='v_test'

ORDER BY collate_schema_name, collate_table_name ASC;

Br, Ari
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