[Week10][Chap3] Feat : 시작-JPQL vs Querydsl(#111)

최송희/querydsl/src/test/java/study/querydsl/entity/QuerydslBasicTest.java

@@ -0,0 +1,70 @@
+package study.querydsl.entity;
+
+import com.querydsl.jpa.impl.JPAQueryFactory;
+import jakarta.persistence.EntityManager;
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.transaction.annotation.Transactional;
+
+import static org.assertj.core.api.Assertions.*;
+
+@SpringBootTest
+@Transactional
+public class QuerydslBasicTest {
+
+    @Autowired
+    EntityManager em;
+
+    JPAQueryFactory queryFactory;
+
+    @BeforeEach //실행전에 돌아간다
+    public void before(){
+        queryFactory = new JPAQueryFactory(em);
+        Team teamA = new Team("teamA");
+        Team teamB = new Team("teamB");
+        em.persist(teamA);
+        em.persist(teamB);
+
+        Member member1 = new Member("member1", 10, teamA);
+        Member member2 = new Member("member2", 20, teamA);
+        Member member3 = new Member("member3", 30, teamB);
+        Member member4 = new Member("member4", 40, teamB);
+        em.persist(member1);
+        em.persist(member2);
+        em.persist(member3);
+        em.persist(member4);
+
+    }
+
+    @Test
+    public void startJPQL(){
+        String qlString =
+                "select m from Member m" +
+                " where m.username = :username";
+        //member1을 찾아라.
+        Member findMember = em.createQuery(qlString, Member.class)
+                .setParameter("username", "member1")
+                .getSingleResult();
+
+        assertThat(findMember.getUsername()).isEqualTo("member1");
+    }
+
+    @Test
+    public void startQuerydsl(){
+        QMember m = new QMember("m");
+        //variable은 식별용
+
+        Member findMember = queryFactory.select(m)
+                .from(m)
+                .where(m.username.eq("member1")) //파라미터 바인딩
+                .fetchOne();
+        /*querydsl 이점 : 1. 컴파일 시점에서 오류를 발견 2. 파라미터 바인딩을 자동으로 실행*/
+
+        assertThat(findMember.getUsername()).isEqualTo("member1");
+    }
+
+
+}