增加 jpa 示例

lab-12/lab-12-mybatis-xml/target/classes/sql/users.sql

@@ -0,0 +1,8 @@
+CREATE TABLE `users` (
+  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '用户编号',
+  `username` varchar(64) COLLATE utf8mb4_bin DEFAULT NULL COMMENT '账号',
+  `password` varchar(32) COLLATE utf8mb4_bin DEFAULT NULL COMMENT '密码',
+  `create_time` datetime DEFAULT NULL COMMENT '创建时间',
+  PRIMARY KEY (`id`),
+  UNIQUE KEY `idx_username` (`username`)
+) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;

lab-13/lab-13-jpa/src/main/java/cn/iocoder/springboot/lab13/jpa/dataobject/UserDO.java

@@ -6,7 +6,8 @@ import java.util.Date;
 /**
  * 用户 DO
  */
-@Entity(name = "users")
+@Entity
+@Table(name = "users")
 public class UserDO {
 
     /**

lab-13/lab-13-jpa/src/main/java/cn/iocoder/springboot/lab13/jpa/repository/UserRepository03.java

@@ -0,0 +1,16 @@
+package cn.iocoder.springboot.lab13.jpa.repository;
+
+import cn.iocoder.springboot.lab13.jpa.dataobject.UserDO;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.repository.PagingAndSortingRepository;
+
+import java.util.Date;
+
+public interface UserRepository03 extends PagingAndSortingRepository<UserDO, Integer> {
+
+    UserDO findByUsername(String username);
+
+    Page<UserDO> findByCreateTimeAfter(Date createTime, Pageable pageable);
+
+}

lab-13/lab-13-jpa/src/main/java/cn/iocoder/springboot/lab13/jpa/repository/UserRepository04.java

@@ -0,0 +1,24 @@
+package cn.iocoder.springboot.lab13.jpa.repository;
+
+import cn.iocoder.springboot.lab13.jpa.dataobject.UserDO;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.PagingAndSortingRepository;
+import org.springframework.data.repository.query.Param;
+
+public interface UserRepository04 extends PagingAndSortingRepository<UserDO, Integer> {
+
+    @Query("SELECT u FROM UserDO u WHERE u.username = ?1")
+    UserDO findByUsername01(String username);
+
+    @Query("SELECT u FROM UserDO u WHERE u.username = :username")
+    UserDO findByUsername02(@Param("username") String username);
+
+    @Query(value = "SELECT * FROM users u WHERE u.username = :username", nativeQuery = true)
+    UserDO findByUsername03(@Param("username") String username);
+
+    @Query("UPDATE UserDO  u SET u.username = :username WHERE u.id = :id")
+    @Modifying
+    int updateUsernameById(Integer id, String username);
+
+}

lab-13/lab-13-jpa/src/test/java/cn/iocoder/springboot/lab13/jpa/repository/UserRepository03Test.java

@@ -0,0 +1,41 @@
+package cn.iocoder.springboot.lab13.jpa.repository;
+
+import cn.iocoder.springboot.lab13.jpa.dataobject.UserDO;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Pageable;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import java.util.Calendar;
+import java.util.Date;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest
+public class UserRepository03Test {
+
+    @Autowired
+    private UserRepository03 userRepository;
+
+    @Test
+    public void testFindByUsername() {
+        UserDO user = userRepository.findByUsername("yunai");
+        System.out.println(user);
+    }
+
+    @Test
+    public void testFindByCreateTimeAfter() {
+        // 创建分页条件
+        Pageable pageable = PageRequest.of(1, 10);
+        // 执行分页操作
+        Date createTime = new Date(2018 - 1990, Calendar.FEBRUARY, 24); // 临时 Demo ，实际不建议这么写
+        Page<UserDO> page = userRepository.findByCreateTimeAfter(createTime, pageable);
+        // 打印
+        System.out.println(page.getTotalElements());
+        System.out.println(page.getTotalPages());
+    }
+
+}

lab-13/lab-13-jpa/src/test/java/cn/iocoder/springboot/lab13/jpa/repository/UserRepository04Test.java

@@ -0,0 +1,45 @@
+package cn.iocoder.springboot.lab13.jpa.repository;
+
+import cn.iocoder.springboot.lab13.jpa.dataobject.UserDO;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import javax.transaction.Transactional;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest
+public class UserRepository04Test {
+
+    @Autowired
+    private UserRepository04 userRepository;
+
+    @Test
+    public void testFindIdByUsername01() {
+        UserDO user = userRepository.findByUsername01("yunai");
+        System.out.println(user);
+    }
+
+    @Test
+    public void testFindIdByUsername02() {
+        UserDO user = userRepository.findByUsername02("yunai");
+        System.out.println(user);
+    }
+
+    @Test
+    public void testFindIdByUsername03() {
+        UserDO user = userRepository.findByUsername03("yunai");
+        System.out.println(user);
+    }
+
+    @Test
+    // 更新操作，需要在事务中。
+    // 在单元测试中，事务默认回滚，所以胖友可能怎么测试，事务都不更新。
+    @Transactional
+    public void testUpdateUsernameById() {
+        userRepository.updateUsernameById(5, "yudaoyuanma");
+    }
+
+}