[Bug] Aula Consulta e a primeira funcao

Fizemos conforme a aula a insercao de dados nas tabelas, porem, ao executar as consulta da erro, ou melhor, o retorno do resultado retorna Null

SELECT * FROM alugueis; 

Null

SELECT * FROM alugueis;
SELECT * FROM avaliacoes;
SELECT * FROM clientes;
SELECT * FROM enderecos;
SELECT * FROM hospedagens;
SELECT * FROM proprietarios;

Todos Null

SELECT COUNT(*) FROM alugueis;
SELECT COUNT(*) FROM avaliacoes;
SELECT COUNT(*) FROM clientes;
SELECT COUNT(*) FROM enderecos;
SELECT COUNT(*) FROM hospedagens;
SELECT COUNT(*) FROM proprietarios;

Count (*) 0

SELECT COUNT(*) FROM alugueis;
SELECT COUNT(*) FROM avaliacoes;
SELECT COUNT(*) FROM clientes;
SELECT COUNT(*) FROM enderecos;
SELECT COUNT(*) FROM hospedagens;
SELECT COUNT(*) FROM proprietarios;

Todos os campos retorna 0

 SELECT
  (SELECT COUNT(*) FROM alugueis) as alugueis,
  (SELECT COUNT(*) FROM avaliacoes) as avaliacoes,
  (SELECT COUNT(*) FROM clientes) as clientes,
  (SELECT COUNT(*) FROM enderecos) as enderecos,
  (SELECT COUNT(*) FROM hospedagens) as hospedagens,
  (SELECT COUNT(*) FROM proprietarios) as proprietarios;

Aqui somente o campo enderecos retorna 2200, os demais campos, todos 0.

Como podemos fazer para resolver esses probleminhas?

Muito obrigada!

Claudia