Spring Repository 自定义查询拼写评估始终为空答案

【问题标题】：Spring Repository Custom Query Spel Evaluation Always NullSpring Repository 自定义查询拼写评估始终为空
【发布时间】：2016-04-17 08:09:20
【问题描述】：

每次我在存储库中调用 findByFirstNameContainingOrLastNameContaining 函数时都会收到错误消息：

org.springframework.expression.spel.SpelEvaluationException: EL1007E:(pos 0): Property or field 'firstName' cannot be found on null

我的查询错了吗？我对这个错误一无所知

这是我的文件：

Person.java

package com.model;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class Person {

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    long id;

    String firstName;

    String lastName;

    public String getFirstName() {
        return firstName;
    }
    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }
    public String getLastName() {
        return lastName;
    }
    public void setLastName(String lastName) {
        this.lastName = lastName;
    }
}

PersonRepository.java

package com.repositories;

import com.model.Person;
import java.util.List;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.CrudRepository;
import org.springframework.data.repository.query.Param;

public interface PersonRepository extends CrudRepository<Person, Long> {
    @Query("SELECT p FROM Person p WHERE p.firstName LIKE %:firstName% OR "
            + "p.firstName LIKE %:lastName% OR "
            + "p.lastName LIKE %:lastName% OR "
            + "p.lastName LIKE %:firstName%")
    public List<Person> findByFirstNameContainingOrLastNameContaining(
        @Param(value = "firstName") String firstName, 
        @Param(value = "lastName") String lastName
    );
}

【问题讨论】：

标签： spring jpa spring-data spring-data-jpa

【解决方案1】：

只需将 %xxx% 替换为 :{parameter} 即可。

package com.example.repository;

import com.example.model.Employee;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param;

import java.util.List;


public interface EmployeeRepository extends JpaRepository<Employee, Long> {

@Query("SELECT e FROM Employee e WHERE e.firstName LIKE :firstName OR "
    + "e.firstName LIKE :lastName OR "
    + "e.lastName LIKE :lastName OR "
    + "e.lastName LIKE :firstName")
List<Employee> findByFirstNameContainingOrLastNameContaining(
    @Param(value = "firstName") String firstName,
    @Param(value = "lastName") String lastName
);
}

【讨论】：