title: How can I define a composite primary key in SQL?
body: <p>How can I define a composite primary key consisting of two fields in SQL?</p>
  <p>I want to make a table name <code>voting</code> with fields <code>QuestionID</code>, <code>MemberID</code>, and <code>vote</code>. And the Composite primary key consists of the fields <code>QuestionID</code> and <code>MemberID</code>.</p>
  <p>How should I do this?</p>