SpringDataJPA的自定义操作

a. @Query
i. 查询如果返回单个实体 就用实体对象接收 ， 如果是多个需要通过集合
ii. 参数设置方式

1. 索引 ： ?数字

// 查询
     @Query("FROM Customer where custName=?1 ")
     List findCustomerByCustName1(@Param("custName") String custName);

3. 具名： :参数名 结合@Param注解指定参数名字

 @Query("FROM Customer where custName=:custName ")
    List findCustomerByCustName(@Param("custName") String custName);

iii. 增删改：
5. 要加上事务的支持：
@Transactional // 通常会放在业务逻辑层上面去声明
@Modifying // 通知springdatajpa 是增删改的操作
7. 如果是插入方法：一定只能在hibernate下才支持 （Insert into
…select )

// 修改
    @Transactional //实际中加在业务逻辑上
    @Modifying   // 通知springdatajpa 是增删改的操作
    @Query("UPDATE Customer c set c.custName=:custName where c.custId=:id")
    int updateCustomer(@Param("custName") String custName,@Param("id")Long id);


    @Transactional
    @Modifying   // 通知springdatajpa 是增删改的操作
    @Query("DELETE FROM Customer c where c.custId=?1")
    int deleteCustomer(Long id);

    // 新增  JPQL
    @Transactional
    @Modifying   // 通知springdatajpa 是增删改的操作   Customer (custName)表示只插入custName
    @Query("INSERT INTO Customer (custName) SELECT c.custName FROM Customer c where c.custId=?1")
    int insertCustomerBySelect(Long id);

	//原生的sql需要加,nativeQuery = true
    @Query(value="select * FROM tb_customer where cust_name=:custName "
    ,nativeQuery = true)
    List findCustomerByCustNameBySql(@Param("custName") String custName);

支持的查询方法主题关键字（前缀）
决定当前方法作用
只支持查询和删除

Repository接口中

package com.tuling.repositories;

import com.tuling.pojo.Customer;
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;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;

public interface CustomerMethodNameRepository extends PagingAndSortingRepository {
     
     List findByCustName(String custName);

     
     boolean existsByCustName(String custName);

     
     @Transactional
     @Modifying
     int deleteByCustId(Long custName);

     
     List findByCustNameLike(String custName);

}