title: Column reference is ambiguous in PostgreSQL function
body: <p>I've created a function like this.</p>
  
  <pre><code>create or replace function pesquisar_imoveis_residenciais_venda()
  returns table(preco decimal)
  as $$
  begin
  
      select preco from casa_venda;
  
  end; $$
  
  language 'plpgsql';
  </code></pre>
  
  <p>When I call it</p>
  
  <pre><code>  select pesquisar_imoveis_residenciais_venda()
  </code></pre>
  
  <p>I get the column reference preco is ambiguous.</p>
  
  <p>I've visited some related question. But they are too difficult to follow, very complex functions.</p>