-- Database schema
| architect : id [ TEXT ] primary_key , name [ TEXT ] , nationality [ TEXT ] , gender [ TEXT ] | bridge : architect_id [ INT ] bridge.architect_id = architect.id , id [ INT ] primary_key , name [ TEXT ] , location [ TEXT ] , length_meters [ INT ] , length_feet [ INT ] | mill : architect_id [ INT ] mill.architect_id = architect.id , id [ INT ] primary_key , location [ TEXT ] , name [ TEXT ] , type [ TEXT ] , built_year [ INT ] , notes [ TEXT ] |
-- -- What are the ids, names and genders of the architects who built two bridges or one mill?

SELECT T1.id ,  T1.name ,  T1.gender FROM architect AS T1 JOIN bridge AS T2 ON T1.id  =  T2.architect_id GROUP BY T1.id HAVING count(*)  =  2 UNION SELECT T1.id ,  T1.name ,  T1.gender FROM architect AS T1 JOIN mill AS T2 ON T1.id  =  T2.architect_id GROUP BY T1.id HAVING count(*)  =  1;