Mixed SRID's in trigger stopping qgis from committing changes

Question

I have a trigger that takes a line, grabs its ST_StartPoint and ST_EndPoint and then grabs the nearest point to those endpoints, and assigns a node_id to a column. This Fiddle shows the trigger as well as some example data. When running this trigger, I am getting an error on QGIS stating the following:

Could not commit changes to layer pipes

Errors: ERROR: 1 feature(s) not added.
  
  Provider errors:
      PostGIS error while adding features: ERROR:  Operation on mixed SRID geometries
    CONTEXT:  SQL statement "SELECT 
      j.node_id,
      i.node_id
                                     FROM ST_Dump(ST_SetSRID(NEW.geom,2346)) dump_line,
      LATERAL (SELECT s.node_id,(ST_SetSRID(s.geom,2346)) 
               FROM structures s
               ORDER BY ST_EndPoint((dump_line).geom)<->s.geom 
               LIMIT 1) j (node_id,geom_closest_downstream),
      LATERAL (SELECT s.node_id,(ST_SetSRID(s.geom,2346))
               FROM structures s
               ORDER BY ST_StartPoint((dump_line).geom)<->s.geom 
               LIMIT 1) i (node_id,geom_closest_upstream)"
    PL/pgSQL function sewers."Up_Str"() line 3 at SQL statement
   

I have attempted to resolve the issue by editing the trigger to this but this has not fixed the problem. Any ideas would be greatly appreciated.

Answer 1

The line ORDER BY ST_EndPoint((dump_line).geom)<->s.geom (and the similar one for the start point) is likely the faulty one.

You could, again, declare the CRS of s.geom . Note that by doing this any spatial index on structures would not be used, it would have to be created on ST_SetSRID(geom,2346)

The clean way would be to set the CRS at the column level on the structures table

alter table structures alter column geom TYPE geometry(point,2346) using st_setSRID(geom,2346);