在SpringData中們可是使用繼承介面直接按照規則寫方法名即可完成查詢的方法，不需要寫具體的實現，但是這樣寫又是不能滿足我們的需求，比如子查詢，SpringData中提供了@Query註解可以讓我們寫JPA的語句和原生的SQL語句，那接下來看看怎麼寫JPA的查詢語句和原生的SQL語句。

package com.springdata.study.repository;

import java.util.List;

import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.Repository;
import org.springframework.data.repository.query.Param;

import com.springdata.study.entitys.Person;

//1.實際上Repository是一個口介面，沒有提供任何方法，是一個標記介面
//2.實現了Repository介面就會被spring IOC容器識別為Repository Bean
//		會被納入IOC容器中
//3.Repository介面也可以同@RepositoryDefinition 註解代替，效果是一樣的
//4.介面中的泛型：第一個是那個實體類的Repository，第二個是實體類的主鍵的型別
//@RepositoryDefinition(domainClass=Person.class,idClass=Integer.class)

/**
 * 在Repository介面中申明方法 1.申明方法需要符合一定的規範 2.查詢方法需要以 find | read | get開頭 3.涉及查詢條件時
 * 需要用條件關鍵字連線 4.屬性首字母大寫 5.支援級聯屬性
 * 6.AddressId若當前實體類中有屬性，則優先使用該屬性，若想要使用級聯屬性，需要用下劃線隔開Address_Id
 */

public interface PersonRepositoiry extends Repository<Person, Integer> {
	// select p from Person where p.name = ?
	Person getByName(String name);

	List<Person> findByNameStartingWithAndIdLessThan(String name, Integer id);

	// where name like %? and id < ?
	List<Person> findByNameEndingWithAndIdLessThan(String name, Integer id);

	// where email in ? age < ?
	List<Person> readByEmailInOrAgeLessThan(List<String> emails, int age);

	// 級聯屬性查詢
	// where address.id > ?
	List<Person> findByAddress_IdGreaterThan(Integer is);

	// 可以使用@Query註解在其value屬性中寫JPA語句靈活查詢
	@Query("SELECT p FROM Person p WHERE p.id = (SELECT max(p2.id) FROM Person p2)")
	Person getMaxIdPerson();

	// 在@Query註解中使用佔位符
	@Query(value = "SELECT p FROM Person p where p.name = ?1 and p.email = ?2")
	List<Person> queryAnnotationParam1(String name, String email);

	// 使用命名引數傳遞引數
	@Query(value = "SELECT p FROM Person p where p.name = :name")
	List<Person> queryAnnotationParam2(@Param("name") String name);

	// SpringData可以在引數上新增%
	@Query("SELECT p FROM Person p WHERE p.name LIKE %?1%")
	List<Person> queryAnnotationLikeParam(String name);

	// SpringData可以在引數上新增%
	@Query("SELECT p FROM Person p WHERE p.name LIKE %:name%")
	List<Person> queryAnnotationLikeParam2(@Param("name")String name);

	//在@Query註解中新增nativeQuery=true屬性可以使用原生的SQL查詢
	@Query(value="SELECT count(*) FROM jpa_person", nativeQuery=true)
	long getTotalRow();
	
}
 

下面是這個類的測試類

package com.springdata.study.test;

import java.sql.SQLException;
import java.util.Arrays;
import java.util.List;

import javax.sql.DataSource;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.springdata.study.entitys.Person;
import com.springdata.study.repository.PersonRepositoiry;
import com.springdata.study.service.PersonService;

public class DataSourceTest {

	private ApplicationContext applicationContext;
	private PersonService personService;
	private PersonRepositoiry personRepositoiry;

	{
		applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
		personRepositoiry = applicationContext.getBean(PersonRepositoiry.class);
		personService = applicationContext.getBean(PersonService.class);
	}

	@SuppressWarnings("resource")
	@Test
	public void testDataSource() throws SQLException {
		ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
		DataSource dataSource = applicationContext.getBean(DataSource.class);
		System.out.println(dataSource.getConnection());
	}

	@Test
	public void testSpringdata() {
		Object person = personService.getPerson("LQF");
		System.out.println(person);
	}

	@Test
	public void testFindByNameStartingWithAndIdLessThan() {
		List<Person> persons = personRepositoiry.findByNameStartingWithAndIdLessThan("g", 6);
		persons = personRepositoiry.findByNameEndingWithAndIdLessThan("g", 6);
		System.out.println(persons);
	}
	
	@Test
	public void testReadByEmailInOrAgeLessThan() {
		List<Person> persons = personRepositoiry.readByEmailInOrAgeLessThan(Arrays.asList("
 
[email protected]"), 25);
		System.out.println(persons);
	}
	
	@Test
	public void testFindByAddressIdGreaterThan() {
		personRepositoiry.findByAddress_IdGreaterThan(1);
	}
	
	@Test
	public void testGetMaxIdPerson() {
		Person person = personRepositoiry.getMaxIdPerson();
		System.out.println(person);
	}
	
	@Test
	public void testQueryAnnotationParam() {
		List<Person> persons = personRepositoiry.queryAnnotationParam1("liqingfeng", "
 
[email protected]");
		System.out.println(persons);
	}
	
	@Test
	public void testQueryAnnotationParam2() {
		List<Person> persons = personRepositoiry.queryAnnotationParam2("lqf");
		System.out.println(persons);
	}
	
	@Test
	public void testQueryAnnotationLikeParam() {
		List<Person> persons = personRepositoiry.queryAnnotationLikeParam2("li");
		System.out.println(persons);
	}
	
	@Test
	public void testGetTotalRow() {
		long count = personRepositoiry.getTotalRow();
		System.out.println(count);
	}
	
}