一、使用方法
1、在dao中定义开一个方法，使用方法的参数设置jpql，并且使用方法的返回值接受查询结果，在方法上添加@query注解，在注解中写jpql语句进行增删改查，测试
2、使用原生的sql语句：dao中定义一个方法，在方法中添加@query注解，在注解中添加原生sql语句，并且添加一个属性：nativeQuery=true，测试
3、方法命名规则查询：
通过以肯定的规则，定义一个方法，框架本身就可以根据方法名生成一块个sql语句进行查询，规则：
1、必须以findBy开头
2、查询某个字段，findBy后跟实体类的属性名称
3、如果有多个条件，就在方法后加And后跟实体类的属性名
4、方法的参数对应查询的定义
5、返回值根据返回值的数据类型定义；如果是分页查询，在方法中添加一个参数Pageable即可
二、、编写实现类
package cn.zrf.jpa.entity;
import javax.persistence.*;
@Entity
@Table(name = "cust_customer")
public class Customer {
// 配置主键自增的策略
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Id
@Column(name="cust_id")
private long custId;
@Column(name="cust_name")
private String custName;
@Column(name="cust_source")
private String custSource;
@Column(name="cust_indutry")
private String custIndutry;
@Column(name="cust_level")
private String custLevel;
@Column(name="cust_address")
private String custAddress;
@Column(name="cust_phone")
private String custPhone;
@Override
public String toString() {
return "Customer{" +
"custId=" + custId +
", custName=‘" + custName + ‘\‘‘ +
", custSource=‘" + custSource + ‘\‘‘ +
", custIndutry=‘" + custIndutry + ‘\‘‘ +
", custLevel=‘" + custLevel + ‘\‘‘ +
", custAddress=‘" + custAddress + ‘\‘‘ +
", custPhone=‘" + custPhone + ‘\‘‘ +
‘}‘;
}
public long getCustId() {
return custId;
}
public void setCustId(long custId) {
this.custId = custId;
}
public String getCustName() {
return custName;
}
public void setCustName(String custName) {
this.custName = custName;
}
public String getCustSource() {
return custSource;
}
public void setCustSource(String custSource) {
this.custSource = custSource;
}
public String getCustIndutry() {
return custIndutry;
}
public void setCustIndutry(String custIndutry) {
this.custIndutry = custIndutry;
}
public String getCustLevel() {
return custLevel;
}
public void setCustLevel(String custLevel) {
this.custLevel = custLevel;
}
public String getCustAddress() {
return custAddress;
}
public void setCustAddress(String custAddress) {
this.custAddress = custAddress;
}
public String getCustPhone() {
return custPhone;
}
public void setCustPhone(String custPhone) {
this.custPhone = custPhone;
}
}
三、编写dao
package cn.zrf.jpa.dao;
import cn.zrf.jpa.entity.Customer;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
import org.springframework.data.jpa.repository.Modifying;
import org.springframework.data.jpa.repository.Query;
import java.util.List;
public interface CustomerDao extends JpaRepository<Customer,Long>,JpaSpecificationExecutor<Customer> {
//查询全部
@Query("from Customer")
List<Customer> getAllCustomer();
//查询全部并分页
@Query("from Customer ")
List<Customer> getAllCustomerByPage(Pageable pageable);
//条件查询(根据ID查询)
@Query("from Customer where cust_id = ?")
Customer getCustomerById(Long id);
//根据地址，姓名模糊查询
@Query("from Customer where custAddress like ? and custName like ?")
List<Customer> getCustList(String address,String custName);
//根据ID进行局部更新操作
@Query("update Customer set cust_name=? where custId=?")
@Modifying
void getUpdateById(String name,Long id);
//原生sql语句模糊查询操作
@Query(value = "select * from cust_customer where cust_name like ?",nativeQuery = true)
List<Customer> getCustomerListByNative(String name);
//方法命名规则查询
/**1 应该使用findBy开头
* 2 查询某个字段 findBy后跟实体类的属性的名称
* 3 如果有多个条件 就在方法后加And+实体类的属性名
* 4 方法的参数 对应查询的定义
* 5 返回值根据返回的数据类型定义
* 6 如果需要分页查询 在方法中添加一个参数Pageable 即可
*/
//根据ID查询
Customer findByCustId(Long id);
//根据姓名，地址进行模糊查询
List<Customer> findByCustNameLikeAndCustAddressLike(String name,String address);
//分页查询
List<Customer> findByCustAddressLike(String address, Pageable pageable);
}
四、测试类
package cn.jpa.test;
import cn.zrf.jpa.dao.CustomerDao;
import cn.zrf.jpa.entity.Customer;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.PageRequest;
import org.springframework.test.annotation.Commit;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.transaction.annotation.Transactional;
import java.awt.print.Pageable;
import java.util.List;
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class TestJpql {
@Autowired
CustomerDao customerDao;
//查询全部
@Test
public void getAllCustomerTest(){
List<Customer> list = customerDao.getAllCustomer();
for (Customer customer:list){
System.out.println(customer);
}
}
//查询全部并分页
@Test
public void getAllCustomerByPageTest(){
List<Customer> list = customerDao.getAllCustomerByPage(new PageRequest(0, 3));
for (Customer customer:list){
System.out.println(customer);
}
}
//根据ID查询
@Test
public void getCustomerByIdTest(){
Customer customer = customerDao.getCustomerById(1l);
System.out.println(customer);
}
//根据地址，姓名进行模糊查询
@Test
public void getCuseListTest(){
List<Customer> custList = customerDao.getCustList("%京%", "%长%");
for (Customer customer:custList){
System.out.println(customer);
}
}
//根据ID进行局部更新操作
@Test
@Transactional
@Commit
public void getUpdateByIdTest(){
customerDao.getUpdateById("张无忌",3l);
}
//原生sql语句模糊查询
@Test
public void getCustomerByNativeTest(){
List<Customer> list = customerDao.getCustomerListByNative("%长%");
for (Customer customer:list){
System.out.println(customer);
}
}
//方法命名规则查询测试
//根据ID查询
@Test
public void findByIdTest(){
Customer customer = customerDao.findByCustId(1L);
System.out.println(customer);
}
//根据地址，姓名进行模糊查询
@Test
public void findByCustNameLikeAndAddressLike(){
List<Customer> list = customerDao.findByCustNameLikeAndCustAddressLike("%张%","%京%");
for (Customer customer:list){
System.out.println(customer);
}
}
//根据地址进行分页查询
@Test
public void findByCustAddressLike(){
List<Customer> list = customerDao.findByCustAddressLike("%京%", new PageRequest(0, 3));
for (Customer customer:list){
System.out.println(customer);
}
}
}
原文地址：https://www.cnblogs.com/zhangrongfei/p/11391177.html
时间： 2024-12-10 19:25:18