How to solve the problem with creating a table in mysql using java?

Question

I used @Entity to create a table in mysql. The program runs, but the table isn't created

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>3.0.5</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.springboot.blog</groupId>
    <artifactId>springboot-blog-rest-api</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot-blog-rest-api</name>
    <description>Spring boot blog application rest api&apos;s</description>
    <properties>
        <java.version>17</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>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

application.properties:

spring.datasource.url=jdbc:mysql://localhost:3306/myblog
spring.datasource.username=root
spring.datasource.password=Yourschool2

spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQLDialect

spring.jpa.properties.ddl-auto=update

class Post:

package com.springboot.blog.entity;
import jakarta.persistence.*;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@AllArgsConstructor
@NoArgsConstructor

@Entity
@Table(
        name="posts", uniqueConstraints = {@UniqueConstraint(columnNames = {"title"})}
)
public class Post {
    @Id
    @GeneratedValue(
            strategy =  GenerationType.IDENTITY
    )
    private Long id;

    @Column( name = "title", nullable = false)
    private String title;
    @Column(name = "description", nullable = false)
    private String description;

    @Column(name = "content", nullable = false)
    private String content;
}

And the main method:

package com.springboot.blog;

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

@SpringBootApplication
public class SpringbootBlogRestApiApplication {

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

I tried to delete @Table( name="posts", uniqueConstraints = {@UniqueConstraint(columnNames = {"title"})} ) from Post class. I thought I made wrong properties here. I also tried to сhange @GeneratedValue( strategy = GenerationType.IDENTITY ) to @GeneratedValue( strategy = GenerationType.AUTO )

Nothing helps. I'm new in spring. Can you say what may help to solve the problem?

Answer 1

Please add following property. This is needed to enable an automatic generation of database tables from entities.

spring.jpa.generate-ddl=true