Otdfbt

From a table of point data, there are some groups of points that can define a line (cross sections of a water course). 'cross_section' is the name of the table with the point data, geometrypoint the column with the geometry. 'code_sequence_nr' is the column that specifies the point sequence, so it becomes a nice line.
To make lines from groups of point data I have the following query:

CREATE TABLE cross_section_lines AS
SELECT st_makeline(geometrypoint) as cross_section,
 cross_section.profile_code,
 cross_section.administrative_area_id,
 FROM (SELECT geometrypoint, profile_code, administrative_area_id
 FROM cross_section
 ORDER BY code_sequence_nr) cross_section
 GROUP BY cross_section.profile_code, cross_section.administrative_area_id;

Now I need more information than the columns used for grouping, but if I add a column like this:

CREATE TABLE cross_section_lines AS
SELECT st_makeline(geometrypoint) as cross_section,
 cross_section.profile_code,
 cross_section.administrative_area_id,
 cross_section.profile_type_id
 FROM (SELECT geometrypoint, profile_code, administrative_area_id
 FROM cross_section
 ORDER BY code_sequence_nr) cross_section
 GROUP BY cross_section.profile_code, cross_section.administrative_area_id;

The following error occurs:

ProgrammingError: (psycopg2.errors.UndefinedColumn) column cross_section.profile_type_id does not exist

But that column is certainly there. Now how do I add the profile type (and other usefull columns) to the resulting table that is created?

Since you don't want the column in the GROUP BY section, you would have to aggregate the values of this column.

For instance, you can use STRING_AGG and possibly keep only the distinct values via the DISTINCT keyword.
You may have to cast the column to text as well

SELECT id, string_agg(distinct colA::text, ',')
FROM mytable
GROUP BY id;

profile_type_id is not in your select statement so the outer select can't see it. You need to try something like:

CREATE TABLE cross_section_lines AS
 SELECT st_makeline(geometrypoint) as cross_section,
 cross_section.profile_code,
 cross_section.administrative_area_id,
 cross_section.profile_type_id
 FROM (SELECT geometrypoint, profile_code, administrative_area_id, profile_type_id
 FROM cross_section
 ORDER BY code_sequence_nr) cross_section
 GROUP BY cross_section.profile_code, cross_section.administrative_area_id, cross_section.profile_type_id;