详解Spring Data JPA使用@Query注解（Using @Query）

  /**
   * 模糊匹配
   * @param bauer
   * @return
   */
  @Query("select c from Customer c where c.firstName=?1")
  Customer findByFirstName2(String bauer);

  @Query("select c from Customer c where c.lastName=?1 order by c.id desc")
  List<Customer> findByLastName2(String lastName);

  /**
   * 一个参数，匹配两个字段
   * @param name2
   * @return
   * 这里Param的值和=:后面的参数匹配，但不需要和方法名对应的参数值对应
   */
  @Query("select c from Customer c where c.firstName=:name or c.lastName=:name order by c.id desc")
  List<Customer> findByName(@Param("name") String name2);

  /**
   * 一个参数，匹配两个字段
   * @param name
   * @return
   * 这里的%只能放在占位的前面，后面不行
   */
  @Query("select c from Customer c where c.firstName like %?1")
  List<Customer> findByName2(@Param("name") String name);

  /**
   * 一个参数，匹配两个字段
   * @param name
   * @return
   * 开启nativeQuery=true，在value里可以用原生SQL语句完成查询
   */
  @Query(nativeQuery = true,value = "select * from Customer c where c.first_name like concat('%' ,?1,'%') ")
  List<Customer> findByName3(@Param("name") String name);

 
  /**
   * @Query注解方式查询
   * 查询FirstName为指定字符串
   */
  @RequestMapping("/findByFirstName2")
  public void findByFirstName2(){
    Customer customer = repository.findByFirstName2("Bauer");
    if(customer!=null){
      System.out.println(customer.toString());
    }
    System.out.println("-------------------------------------------");
  }

  /**
   * @Query注解方式查询
   * 查询LastName为指定字符串
   */
  @RequestMapping("/findByLastName2")
  public void findByLastName2(){
    List<Customer> result = repository.findByLastName2("Bauer");
    for (Customer customer:result){
      System.out.println(customer.toString());
    }
    System.out.println("-------------------------------------------");
  }

  /**
   * @Query注解方式查询,
   * 用@Param指定参数，匹配firstName和lastName
   */
  @RequestMapping("/findByName")
  public void findByName(){
    List<Customer> result = repository.findByName("Bauer");
    for (Customer customer:result){
      System.out.println(customer.toString());
    }
    System.out.println("-------------------------------------------");
  }

  /**
   * @Query注解方式查询,使用关键词like
   * 用@Param指定参数，firstName的结尾为e的字符串
   */
  @RequestMapping("/findByName2")
  public void findByName2(){
    List<Customer> result = repository.findByName2("e");
    for (Customer customer:result){
      System.out.println(customer.toString());
    }
    System.out.println("-------------------------------------------");
  }

  /**
   * @Query注解方式查询，模糊匹配关键字e
   */
  @RequestMapping("/findByName3")
  public void findByName3(){
    List<Customer> result = repository.findByName3("e");
    for (Customer customer:result){
      System.out.println(customer.toString());
    }
    System.out.println("-------------------------------------------");
  }