hibernate - “无法识别的 hbm2ddl_auto 值：更新”是什么意思

. ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v1.5.21.RELEASE) 2019-09-18 06:01:37.455 INFO 12248 --- [ main] c.s.mirrorworld.mirrorworldApplication : Starting mirrorworldApplication on LAPTOP-FAS0SHLM with PID 12248 (C:\Users\yueho\eclipse-workspace\mirrorworld\target\classes started by yueho in C:\Users\yueho\eclipse-workspace\mirrorworld) 2019-09-18 06:01:37.466 INFO 12248 --- [ main] c.s.mirrorworld.mirrorworldApplication : No active profile set, falling back to default profiles: default 2019-09-18 06:01:37.766 INFO 12248 --- [ main] s.c.a.AnnotationConfigApplicationContext : Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@2f217633: startup date [Wed Sep 18 06:01:37 CST 2019]; root of context hierarchy 2019-09-18 06:01:43.613 INFO 12248 --- [ main] j.LocalContainerEntityManagerFactoryBean : Building JPA container EntityManagerFactory for persistence unit 'default' 2019-09-18 06:01:43.662 INFO 12248 --- [ main] o.hibernate.jpa.internal.util.LogHelper : HHH000204: Processing PersistenceUnitInfo [ name: default ...] 2019-09-18 06:01:43.955 INFO 12248 --- [ main] org.hibernate.Version : HHH000412: Hibernate Core {5.0.12.Final} 2019-09-18 06:01:43.959 INFO 12248 --- [ main] org.hibernate.cfg.Environment : HHH000206: hibernate.properties not found 2019-09-18 06:01:43.962 INFO 12248 --- [ main] org.hibernate.cfg.Environment : HHH000021: Bytecode provider name : javassist 2019-09-18 06:01:44.282 INFO 12248 --- [ main] o.hibernate.annotations.common.Version : HCANN000001: Hibernate Commons Annotations {5.0.1.Final} 2019-09-18 06:01:51.899 INFO 12248 --- [ main] org.hibernate.dialect.Dialect : HHH000400: Using dialect: org.hibernate.dialect.MySQL5Dialect

spring.datasource.url=jdbc:mysql://127.0.0.1:3306/mirrorworld spring.datasource.username=root spring.datasource.password=mirror spring.datasource.driver-class-name=com.mysql.jdbc.Driver spring.datasource.max-idle=10 spring.datasource.max-wait=10000 spring.datasource.min-idle=5 spring.datasource.initial-size=5 server.port=8011 server.session.timeout=10 server.tomcat.uri-encoding=UTF-8 spring.jpa.database=MYSQL spring.jpa.show-sql=true spring.jpa.hibernate.format_sql=false spring.jpa.generate-ddl=true spring.jpa.hibernate.ddl-auto=update spring.jpa.hibernate.naming_strategy=org.hibernate.cfg.ImprovedNamingStrategy spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5Dialect

@EntityScan ( basePackages = { "com.stepforward.mirrorworld.p3_application_bean.Unit" } ) @EnableJpaRepositories ( basePackages = { "com.stepforward.mirrorworld.p3_application_bean.Unit" } ) @SpringBootApplication public class mirrorworldApplication { ...... } **3.ENTITY** ============ @Entity public class Unit_Quantity extends Thing { @Id @GenericGenerator(name="assigned", strategy="assigned") @GeneratedValue(generator="assigned") @Column(nullable=false,length=100) private String Id; @Column(nullable=false,length=150) private String Name; @Column(nullable=false,length=20) private String Unit_Quantity_Type; @Column(nullable=false,length=20) private String Symbol; @Column(nullable=true,length=100) private String Formula; ...... }