SELECT c.relname  AS table,
         a.attnum AS ordinal_position,
         a.attname AS column_name,
         t.typname AS data_type,
         a.attlen AS character_maximum_length,
         a.atttypmod AS modifier,
         a.attnotnull AS notnull,
         a.atthasdef AS hasdefault,
         col_description(a.attrelid, a.attnum) as field_comment
    FROM pg_class c,
         pg_attribute a,
         pg_type t
   WHERE a.attnum >  0 
     AND a.attrelid = c.oid
     AND a.atttypid = t.oid
ORDER BY c.relname,a.attnum;