title: I need an sql query that gives me a teacher who teach two specified subject
body: <p>I have a database with teachers and students and i need to find out which teacher  teach subject A and subject B.</p>
  
  <pre><code>select nameteacher
  from teacher inner join 
       university 
       on teacher.codt = university.codt inner join 
       subject 
       on university.coddisc = subject.coddisc
  where subjects=('A') AND subjects=('B');
  </code></pre>
  
  <p>my version doesn't work what should i do ?</p>