JPQL

public void startJPQL() {
		// JPQL로 먼저 써보기 !!
		String qlString = "select m from Member m where m.username= :username";

    // 1. member1을 찾아라
    Member findMember = em.createQuery(qlString, Member.class)
        .setParameter("username", "m1")
        .getSingleResult();

    Assertions.assertThat(findMember.getUsername()).isEqualTo("m1");
}

QueryDls

   public void startQuerydsl() {
        JPAQueryFactory queryFactory = new JPAQueryFactory(em);
        QMember m = new QMember("m");

        Member findMember = queryFactory
            .select(m)
            .from(m)
            .where(m.username.eq("m1"))
            .fetchOne();

        Assertions.assertThat(findMember.getUsername()).isEqualTo("m1");

    }