spring boot data jpa mysql无法创建数据库

Posted 2023-02-26

【中文标题】spring boot data jpa mysql无法创建数据库

【英文标题】：spring boot data jpa mysql could not create database

【发布时间】：2016-10-11 23:55:42

【问题描述】：

我是春天的新人 我将发布我的代码， 那个application.properties

spring.datasource.url=jdbc:mysql://localhost/spring
spring.datasource.username=root
spring.datasource.password=
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.jpa.database-platform=org.hibernate.dialect.MySQLDialect
spring.jpa.hibernate.ddl-auto=update

这是我的实体

    package 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)
private long id;
private String name;
private String phone;
private String adresse;
public long getId() 
    return id;

public void setId(long id) 
    this.id = id;

public String getName() 
    return name;

public void setName(String name) 
    this.name = name;

public String getPhone() 
    return phone;

public void setPhone(String phone) 
    this.phone = phone;

public String getAdresse() 
    return adresse;

public void setAdresse(String adresse) 
    this.adresse = adresse;

public Person(long id, String name, String phone, String adresse) 
    super();
    this.id = id;
    this.name = name;
    this.phone = phone;
    this.adresse = adresse;

public Person() 
    super();

这是存储库

package repositry;



import org.springframework.data.jpa.repository.JpaRepository;


import model.Person;

public interface PersonRespositry extends  JpaRepository<Person, Long>  

和我的控制器

   package contoller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import model.Person;

import repositry.PersonRespositry;

@RestController
public class PersonController 

    PersonRespositry rp;
    @Autowired
    public  PersonController(PersonRespositry rp) 
        // TODO Auto-generated constructor stub
        this.rp=rp;
    


    @RequestMapping("/find")
    public Person find(long id)
        return rp.findOne(id);
    

    @RequestMapping("/findall")
    public List<Person> findall()
        return rp.findAll();
    
    @RequestMapping(value="/hello")
    public String Demo()
        return "Hello world !!";
    
    @RequestMapping(value="/create", method=RequestMethod.GET)
    public String create()
        Person p=new Person();
        p.setName("med");
        p.setPhone("233888");
        p.setAdresse("rue ");
        rp.save(p);
        return " success";
    

这是项目的架构师：

当我运行应用程序时，数据库不会生成，只有 localhost:8080 正在运行。

【问题讨论】：

您必须先手动创建架构（数据库）。然后运行应用程序，应用程序应该在模式中创建表

我创建了架构

【参考方案1】：

您的问题是Application.java 的位置。

@ComponentScan在带有注释的类的包中（@SpringBootApplication 包含@ComponentScan）和该包的子包中查找 Spring bean。

我已经提供了一个非常相似的设置示例。

请看这里：https://***.com/a/27983870/2576531

此外，Robert Moskal 的暗示是正确的。数据库本身必须已经存在。只有表会自动创建。

【参考方案2】：

如果您想创建数据，您需要使用 create 或 create-drop。如果您使用的是 mysql 之类的东西，则至少需要创建数据库。将为您创建表格。

我在针对生产数据库实例执行此操作时非常小心。

【讨论】：

确保 spring.jpa.hibernate.ddl-auto=update 它是创建或更新数据库

【参考方案3】：

否则对我来说它不适用于@componentScan，但它现在可以在主类中使用@EntityScan(basePackages = "com.jwt.entites" ) 来扫描实体类..

【参考方案4】：

这不是答案，但这是一个示例。我想这会对你有所帮助

//Pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.wisdom.spring.myjdbc</groupId>
    <artifactId>spring_boot_jpa</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>spring_boot_jpa</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>


//application Config

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost/wisdom
spring.datasource.username=root
spring.datasource.password=8855
spring.jpa.generate-ddl=true
spring.jpa.properties.hibernate.jdbc.lob.non_contextual_creation=true
server.port = 8585



package com.wisdom.spring.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;


import com.wisdom.spring.model.students;
import com.wisdom.spring.repo.students_repo;

@RestController
@RequestMapping("/students")
public class studentController 
    @Autowired
    students_repo STDRepo;

    @GetMapping(value = "/a")
    public String a() 
        return "hello";
    

    @GetMapping(value = "/save")
    public List<students> getStudents()

        System.out.println("Data returned");
        return STDRepo.findAll();
    

    @PostMapping(value = "/savestd")
    public void saveBurger(students student) 
        STDRepo.save(student);
    




package com.wisdom.spring.model;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;

@Entity
public class students 
    @Id
    @Column
    private int s_id;

    @Column
    private String name;

    @Column
    private String address;

    public students() 

    

    public students(int s_id, String name, String address) 
        this.s_id = s_id;
        this.name = name;
        this.address = address;
    

    public int getS_id() 
        return s_id;
    

    public void setS_id(int s_id) 
        this.s_id = s_id;
    

    public String getName() 
        return name;
    

    public void setName(String name) 
        this.name = name;
    

    public String getAddress() 
        return address;
    

    public void setAddress(String address) 
        this.address = address;
    








package com.wisdom.spring.repo;

import org.springframework.data.jpa.repository.JpaRepository;

import com.wisdom.spring.model.students;

public interface students_repo extends JpaRepository<students,String> 






package com.wisdom.spring;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class SpringBootJpaApplication 

    public static void main(String[] args) 
        SpringApplication.run(SpringBootJpaApplication.class, args);