无法执行语句； SQL [不适用]；约束[PRIMARY]；嵌套异常是 org.hibernate.exception.ConstraintViolationException答案

【问题标题】：could not execute statement; SQL [n/a]; constraint [PRIMARY]; nested exception is org.hibernate.exception.ConstraintViolationException无法执行语句； SQL [不适用]；约束[PRIMARY]；嵌套异常是 org.hibernate.exception.ConstraintViolationException
【发布时间】：2019-06-06 18:18:15
【问题描述】：

SQL [不适用]；约束 [PRIMARY];

我使用 Java/Spring Boot 创建了一个 CRUD RESTful API 应用程序。我有一个 MariaDB，里面有员工列表和相关数据。我使用 MySQL Workbench 作为我的 SQL 客户端。

运行 Spring Boot 应用程序时没有错误。我的数据库中没有错误。获取数据库中所有工程师的 API 时没有错误。

我的“GET”请求工作正常；但是，“POST”没有。如果不使用 MySQL WB 直接插入数据库，我无法创建新员工。

我希望能够通过Postman. 使用 API 创建新员工

如您所见，抛出了一个 ConstraintViolationException。约束是我的主键，即“id”。我已在 MySQL WB 中将其设置为自动递增。

这是我的工程师类的代码：

package engineermanagement.model;

import org.springframework.data.jpa.domain.support.AuditingEntityListener;
import javax.persistence.*;

@Entity
@Table(name = "Engineers")
@EntityListeners(AuditingEntityListener.class)
public class Engineer {

    private Long id;
    private String firstName;
    private String lastName;
    private String sid;
    private String email;
    private String manager;
    private Boolean teamLead;
    private String groupName;
    private String shift;
    private int startTime;
    private int endTime;


    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    public Long getId() {
        return id;
    }
    public void setId(Long id) {
        this.id = id;
    }

    @Column(name = "first_name", nullable = false)
    public String getFirstName() {
        return firstName;
    }
    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    @Column(name = "last_name", nullable = false)
    public String getLastName() {
        return lastName;
    }
    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    @Column(name = "eid", nullable = false)
    public String getEid() {
        return eid;
    }
    public void setEid(String eid) {
        this.sid = eid;
    }

    @Column(name = "email", nullable = false)
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }

    @Column(name = "manager", nullable = false)
    public String getManager() {
        return manager;
    }
    public void setManager(String manager) {
        this.manager = manager;
    }

    @Column(name = "teamlead", nullable = false)
    public Boolean getTeamLead() {
        return teamLead;
    }
    public void setTeamLead(Boolean teamLead) {
        this.teamLead = teamLead;
    }

    @Column(name = "group_name", nullable = false)
    public String getGroupName() {
        return groupName;
    }
    public void setGroupName(String groupName) {
        this.groupName = groupName;
    }

    @Column(name = "shift", nullable = false)
    public String getShift() {
        return shift;
    }
    public void setShift(String shift) {
        this.shift = shift;
    }

    @Column(name = "start_time", nullable = false)
    public int getStartTime() {
        return startTime;
    }
    public void setStartTime(int startTime) {
        this.startTime = startTime;
    }

    @Column(name = "end_time", nullable = false)
    public int getEndTime() {
        return endTime;
    }
    public void setEndTime(int endTime) {
        this.endTime = endTime;
    }
}

这是我的 EngineerController 类的代码：

package jpmchase.controller;

import jpmchase.exception.*;
import jpmchase.model.Engineer;
import jpmchase.repository.EngineerRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import javax.validation.Valid;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


@RestController
@RequestMapping("/api/v1")
public class EngineerController {

    @Autowired
    private EngineerRepository engineerRepository;

    @GetMapping("/engineers")
    public List<Engineer> getAllEngineers() {
        return engineerRepository.findAll();
    }

    @GetMapping("/engineers/{id}")
    public ResponseEntity<Engineer> getEngineerById(
            @PathVariable(value = "id") Long engineerId) throws ResourceNotFoundException {
        Engineer engineer = engineerRepository.findById(engineerId)
                .orElseThrow(() -> new ResourceNotFoundException("Engineer not found on :: "+ engineerId));
        return ResponseEntity.ok().body(engineer);
    }

    @PostMapping("/engineers")
    public Engineer createEngineer(@Valid @RequestBody Engineer engineer) {
        return engineerRepository.save(engineer);
    }

    @PutMapping("/engineers/{id}")
    public ResponseEntity<Engineer> updateEngineer(
            @PathVariable(value = "id") Long engineerId,
            @Valid @RequestBody Engineer engineerDetails) throws ResourceNotFoundException {
        Engineer engineer = engineerRepository.findById(engineerId)
                .orElseThrow(() -> new ResourceNotFoundException("Engineer not found on :: "+ engineerId));
        engineer.setId(engineerDetails.getId());
        engineer.setFirstName(engineerDetails.getFirstName());
        engineer.setLastName(engineerDetails.getLastName());
        engineer.setSid(engineerDetails.getSid());
        engineer.setEmail(engineerDetails.getEmail());
        engineer.setTeamLead(engineerDetails.getTeamLead());
        engineer.setManager(engineerDetails.getManager());
        engineer.setShift(engineerDetails.getShift());
        engineer.setStartTime(engineerDetails.getStartTime());
        engineer.setEndTime(engineerDetails.getEndTime());

//      engineer.setUpdatedAt(new Date());
        final Engineer updatedEngineer = engineerRepository.save(engineer);
        return ResponseEntity.ok(updatedEngineer);
    }

    @DeleteMapping("/engineers/{id}")
    public Map<String, Boolean> deleteEngineer(
            @PathVariable(value = "id") Long engineerId) throws Exception {
        Engineer engineer = engineerRepository.findById(engineerId)
                .orElseThrow(() -> new ResourceNotFoundException("Engineer not found on :: "+ engineerId));

        engineerRepository.delete(engineer);
        Map<String, Boolean> response = new HashMap<>();
        response.put("deleted", Boolean.TRUE);
        return response;
    }
}

使用 Postman，我试图“发布”一个新的“测试”员工，但由于上述限制而失败。任何帮助将不胜感激...

完整的堆栈跟踪：

2019-01-11 15:26:50.605  WARN 15276 --- [nio-8080-exec-6] o.h.engine.jdbc.spi.SqlExceptionHelper   : SQL Error: 1062, SQLState: 23000
2019-01-11 15:26:50.606 ERROR 15276 --- [nio-8080-exec-6] o.h.engine.jdbc.spi.SqlExceptionHelper   : Duplicate entry '68' for key 'PRIMARY'
2019-01-11 15:26:50.606 ERROR 15276 --- [nio-8080-exec-6] o.h.i.ExceptionMapperStandardImpl        : HHH000346: Error during managed flush [org.hibernate.exception.ConstraintViolationException: could not execute statement]
2019-01-11 15:26:50.657  WARN 15276 --- [nio-8080-exec-6] .m.m.a.ExceptionHandlerExceptionResolver : Resolved exception caused by Handler execution: org.springframework.dao.DataIntegrityViolationException: could not execute statement; SQL [n/a]; constraint [PRIMARY]; nested exception is org.hibernate.exception.ConstraintViolationException: could not execute statement

【问题讨论】：

完整的例外是什么？导致错误的有效载荷是什么？换句话说，堆栈跟踪告诉您缺少什么？违反约束意味着您可能正试图在数据库中使用不可为空的 null 值。
编辑帖子以包含堆栈跟踪。
Duplicate entry '68' for key 'PRIMARY' 有一个重复的主键。看看@SequenceGenerator
@sango.gif 你找到解决办法了吗？
我遇到了同样的错误

标签： java mysql api mariadb postman

【解决方案1】：

org.hibernate.exception.ConstraintViolationException,

异常约束违规意味着您将数据库字段设置为非空、唯一等。数据库在将数据插入表之前检查数据。如果任何一个条件不匹配，您将获得 ConstraintViolationException。

在您的情况下，您违反了 PRIMARY 键。所以检查你的数据库表工程师“id = 68”是否存在。如果存在，请删除该行。

【讨论】：

【解决方案2】：

我遇到了同样的问题，原因是这样的 o.h.engine.jdbc.spi.SqlExceptionHelper : Duplicate entry '68' for key 'PRIMARY'.

Hibernate 正在尝试为新的 Engineer 生成一个 Id，但是当它尝试遵循 @GeneratedValue(strategy = GenerationType.AUTO) 指定的生成策略时，它会得到一个已经存在的 Id。这很可能是因为您手动向 Engineer 表添加了新行，该表与 Hibernate 生成的下一个 Id 值一起折叠。

此外，如果您多次尝试插入新的 Engineer，您最终会成功，因为 Hibernate 会为下一个插入请求增加 Id，直到找到一个不存在的 Id。

要解决该问题，您可以将 Id 生成策略更改为 @GeneratedValue(strategy = GenerationType.IDENTITY) 或继续尝试插入，直到 Hibernate 获得未使用的 Id 值（如果您想保持相同的生成策略）

【讨论】：