Function to return dynamic set of columns for given table

Question

I have a fields table to store column information for other tables:

CREATE TABLE public.fields (
   schema_name varchar(100), 
   table_name  va         


        

Answer 1

I think you just need another query to get the list of columns you want.

Maybe something like (this is untested):

create or replace function public.get_table(_schema_name text, _table_name text, active boolean default true) returns setof record as $$
declare
    entity_name text default schema_name || '.' || table_name;
    r record;
    columns varchar;
begin
    -- Get the list of columns
    SELECT string_agg(column_name, ', ')
         INTO columns
         FROM public.fields
         WHERE fields.schema_name = _schema_name
            AND fields.table_name = _table_name
            AND fields.column_visible = TRUE;

    -- Return rows from the specified table
    RETURN QUERY EXECUTE 'select ' || columns || ' from ' || entity_name;

    RETURN;
end
$$
language plpgsql;

Keep in mind that column/table references may need to be surrounded by double quotes if they have certain characters in them.