使用 Spring 引导默认配置通过 JDBC 语句执行 DDL 时出错

Question

这是我尝试将Spring Boot应用程序作为java应用程序运行时收到的错误：
org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL via JDBC Statement
Caused by: java.sql.SQLSyntaxErrorException: Schema 'SA' does not exist

我不得不努力改变pom中冬眠方言.xml(就像在其他关于这个问题的类似主题中写的那样(，但它没有帮助。我还尝试更改主题类和字段的名称。
这是绒球.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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.julian.boot3</groupId>
<artifactId>boot3</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>boot3</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.4.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<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>org.apache.derby</groupId>
<artifactId>derby</artifactId>
<scope>runtime</scope>
</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>
</plugin>
</plugins>
</build>

</project>

主类：

package com.julian.spring;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class App {
public static void main(String[] args) {
SpringApplication.run(App.class, args);
}
}

波乔：

package com.julian.spring.pojo;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
@Table(name="topics")
public class Topic {
@Id
private Integer id;
private String name;
private String description;
public Topic() {
}
public Topic(int id, String name, String description) {
this.id = id;
this.name = name;
this.description = description;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
}

Answer 1

把它放在application.properties文件中的资源下：

spring.jpa.hibernate.ddl-auto=update

Answer 2

我通过将 spring-boot-starter-parent fomr 2.0.4.REALESE 的版本降级到 1.5.1.RELEASE 来解决它

Answer 3

请阅读 https://spring.io/guides/gs/accessing-data-mysql/，这是一个如此常规的问题，如何安排与数据库的连接。

如果您不使用MySQL，则有针对其他数据库的文章，但是对于关系数据库，它们都是一样的。