Trying to insert geometry in existing table (geom field stay empty) using PostGIS?

Question

I'm trying to insert a new line in a big table with the following SQL using PostgreSQL 9.3 and PostGis 2.1.3:

INSERT INTO "Edigeo"."GEOM"(
 cnig, geom_surf, 
 etat, codcom)
 VALUES ('H_11_4_6',
 ST_Difference((SELECT "GEOM_1".geom_surf FROM "Edigeo"."GEOM" AS "GEOM_1" WHERE "GEOM_1".codcom = '73101' AND "GEOM_1".cnig = 'H_1_6_0' LIMIT 1),(SELECT ST_Union("GEOM_2".geom_surf) FROM "Edigeo"."GEOM" AS "GEOM_2" WHERE "GEOM_2".codcom = '73101' AND "GEOM_2".cnig IN ('H_11_4_0','D_1_0_8') AND ST_IsValid("GEOM_2".geom_surf) = True)),
 NULL,
 '73101')

my text field are filled without problem but i have an issue to fill the geometry column (geom_surf) with the ST_Difference statement... It remains empty in the table after the execution.

If i do the same in a select statement, the geometry seems ok.

SELECT ST_Difference((SELECT "GEOM_1".geom_surf FROM "Edigeo"."GEOM" AS "GEOM_1" WHERE "GEOM_1".codcom = '73101' AND "GEOM_1".cnig = 'H_1_6_0' LIMIT 1),(SELECT ST_Union("GEOM_2".geom_surf) FROM "Edigeo"."GEOM" AS "GEOM_2" WHERE "GEOM_2".codcom = '73101' AND "GEOM_2".cnig IN ('H_11_4_0','D_1_0_8') AND ST_IsValid("GEOM_2".geom_surf) = True))

returns

enter image description here

So it looks nice.

But in my table after the insert:enter image description here

Is there an issue with my geometry? or something else? I don't understand why it's not working...

• Vince: Please Edit the question to specify the exact versions of PostgreSQL and PostGIS, include the table creation SQL, and include an actual query that uses the newly inserted row (sometimes pgAdmin doesn't show large geometries).

Answer 1

For large geometries pgAdmin will show a blank field even though there is actually data there. You can verify the existence of data by checking for null geometries:

select * from "Edigeo"."GEOM" where geom_surf is NULL

This tip from the PostGIS website explains in a bit more detail and includes examples of other checks you can carry out.