为什么 H2 在自动创建模式之前尝试在数据库中加载数据？
Why does H2 try to load data in database before auto-creating the schema?
我正在尝试将一些数据加载到我的 H2 数据库中以进行一些测试。为此，我在 src/main/ressources 文件夹中有一个 data-h2.sql 文件。问题是这些数据是在创建模式之前加载的（这是我的理论）。
这是我的代码：
Category.java:
[...]
@Entity
@Table(name="category")
public class Category {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
@NotBlank(message = "label is required")
private String label;
[...]
}
application.properties:
spring.h2.console.enabled=true
spring.datasource.url=jdbc:h2:mem:testdb;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=TRUE;IGNORECASE=TRUE;
spring.datasource.driverClassName=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=sa
spring.jpa.show-sql=true
spring.jpa.generate-ddl=true
spring.jpa.hibernate.ddl-auto=create
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.H2Dialect
server.error.include-message=always
spring.sql.init.platform=h2
数据-h2.sql:
/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET NAMES utf8 */;
/*!50503 SET NAMES utf8mb4 */;
/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;
INSERT INTO `category` VALUES
('Jeu video'),
('Informatique'),
('Electronique'),
('Jeu de société'),
('Electroménager'),
('Littérature'),
('Multimédia'),
('Loisirs');
依赖项pom.xml:
<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.h2database</groupId>
<artifactId>h2</artifactId>
<scope>runtime</scope>
</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>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-validation</artifactId>
</dependency>
</dependencies>
堆栈跟踪：
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSourceScriptDatabaseInitializer' defined in class path resource [org/springframework/boot/autoconfigure/sql/init/DataSourceInitializationConfiguration.class]: Invocation of init method failed; nested exception is org.springframework.jdbc.datasource.init.ScriptStatementFailedException: Failed to execute SQL script statement #1 of URL [file:/C:/Dev/WorkSpaces/STS-4/ECommerce_SpringBoot/target/classes/data-h2.sql]: INSERT INTO `category` VALUES ('Jeu video'), ('Informatique'), ('Electronique'), ('Jeu de société'), ('Electroménager'), ('Littérature'), ('Multimédia'), ('Loisirs'); nested exception is org.h2.jdbc.JdbcSQLSyntaxErrorException: Table "CATEGORY" non trouvée
Table "CATEGORY" not found; SQL statement:
INSERT INTO `category` VALUES ('Jeu video'), ('Informatique'), ('Electronique'), ('Jeu de société'), ('Electroménager'), ('Littérature'), ('Multimédia'), ('Loisirs') [42102-200]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1786) ~[spring-beans-5.3.7.jar:5.3.7]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:602) ~[spring-beans-5.3.7.jar:5.3.7]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524) ~[spring-beans-5.3.7.jar:5.3.7]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean[=14=](AbstractBeanFactory.java:335) ~[spring-beans-5.3.7.jar:5.3.7]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.7.jar:5.3.7]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.7.jar:5.3.7]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.7.jar:5.3.7]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322) ~[spring-beans-5.3.7.jar:5.3.7]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.7.jar:5.3.7]
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1154) ~[spring-context-5.3.7.jar:5.3.7]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:908) ~[spring-context-5.3.7.jar:5.3.7]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.7.jar:5.3.7]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.5.0.jar:2.5.0]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758) ~[spring-boot-2.5.0.jar:2.5.0]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:438) ~[spring-boot-2.5.0.jar:2.5.0]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:337) ~[spring-boot-2.5.0.jar:2.5.0]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1336) ~[spring-boot-2.5.0.jar:2.5.0]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1325) ~[spring-boot-2.5.0.jar:2.5.0]
at zit.demo.ecommerce_springboot.ECommerceSpringBootApplication.main(ECommerceSpringBootApplication.java:10) ~[classes/:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:564) ~[na:na]
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) ~[spring-boot-devtools-2.5.0.jar:2.5.0]
Caused by: org.springframework.jdbc.datasource.init.ScriptStatementFailedException: Failed to execute SQL script statement #1 of URL [file:/C:/Dev/WorkSpaces/STS-4/ECommerce_SpringBoot/target/classes/data-h2.sql]: INSERT INTO `category` VALUES ('Jeu video'), ('Informatique'), ('Electronique'), ('Jeu de société'), ('Electroménager'), ('Littérature'), ('Multimédia'), ('Loisirs'); nested exception is org.h2.jdbc.JdbcSQLSyntaxErrorException: Table "CATEGORY" non trouvée
我做错了什么？
好的，我在这里找到了解决方案
By default, data.sql scripts are now run before Hibernate is
initialized. This aligns the behavior of basic script-based
initialization with that of Flyway and Liquibase. If you want to use
data.sql to populate a schema created by Hibernate, set
spring.jpa.defer-datasource-initialization to true.
通过在 application.properties 文件中添加 spring.jpa.defer-datasource-initialization=true 解决了问题。
对于 Spring 引导 2.4X 和更高版本，事情已经改变了一点。
data.sql 脚本在 hibernate 初始化之前运行。这意味着如果你在 class-path 中有这个文件并且你没有已经创建的模式，那么 Spring 错误说 schema 不存在。
正如许多其他人的回答，我们可以在下面使用 属性 在休眠已经创建模式后推迟初始化。
spring.jpa.defer-datasource-initialization=true
以上添加完成了内存数据库的工作。但是，如果您使用其他数据库，如 PostGresSql 或 mysql，您还必须在 属性 下面添加。
spring:
sql:
init:
mode: always
我正在尝试将一些数据加载到我的 H2 数据库中以进行一些测试。为此，我在 src/main/ressources 文件夹中有一个 data-h2.sql 文件。问题是这些数据是在创建模式之前加载的（这是我的理论）。
这是我的代码：
Category.java:
[...]
@Entity
@Table(name="category")
public class Category {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
@NotBlank(message = "label is required")
private String label;
[...]
}
application.properties:
spring.h2.console.enabled=true
spring.datasource.url=jdbc:h2:mem:testdb;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=TRUE;IGNORECASE=TRUE;
spring.datasource.driverClassName=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=sa
spring.jpa.show-sql=true
spring.jpa.generate-ddl=true
spring.jpa.hibernate.ddl-auto=create
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.H2Dialect
server.error.include-message=always
spring.sql.init.platform=h2
数据-h2.sql:
/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET NAMES utf8 */;
/*!50503 SET NAMES utf8mb4 */;
/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;
INSERT INTO `category` VALUES
('Jeu video'),
('Informatique'),
('Electronique'),
('Jeu de société'),
('Electroménager'),
('Littérature'),
('Multimédia'),
('Loisirs');
依赖项pom.xml:
<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.h2database</groupId>
<artifactId>h2</artifactId>
<scope>runtime</scope>
</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>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-validation</artifactId>
</dependency>
</dependencies>
堆栈跟踪：
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSourceScriptDatabaseInitializer' defined in class path resource [org/springframework/boot/autoconfigure/sql/init/DataSourceInitializationConfiguration.class]: Invocation of init method failed; nested exception is org.springframework.jdbc.datasource.init.ScriptStatementFailedException: Failed to execute SQL script statement #1 of URL [file:/C:/Dev/WorkSpaces/STS-4/ECommerce_SpringBoot/target/classes/data-h2.sql]: INSERT INTO `category` VALUES ('Jeu video'), ('Informatique'), ('Electronique'), ('Jeu de société'), ('Electroménager'), ('Littérature'), ('Multimédia'), ('Loisirs'); nested exception is org.h2.jdbc.JdbcSQLSyntaxErrorException: Table "CATEGORY" non trouvée
Table "CATEGORY" not found; SQL statement:
INSERT INTO `category` VALUES ('Jeu video'), ('Informatique'), ('Electronique'), ('Jeu de société'), ('Electroménager'), ('Littérature'), ('Multimédia'), ('Loisirs') [42102-200]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1786) ~[spring-beans-5.3.7.jar:5.3.7]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:602) ~[spring-beans-5.3.7.jar:5.3.7]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524) ~[spring-beans-5.3.7.jar:5.3.7]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean[=14=](AbstractBeanFactory.java:335) ~[spring-beans-5.3.7.jar:5.3.7]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.7.jar:5.3.7]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.7.jar:5.3.7]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.7.jar:5.3.7]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322) ~[spring-beans-5.3.7.jar:5.3.7]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.7.jar:5.3.7]
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1154) ~[spring-context-5.3.7.jar:5.3.7]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:908) ~[spring-context-5.3.7.jar:5.3.7]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.7.jar:5.3.7]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.5.0.jar:2.5.0]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758) ~[spring-boot-2.5.0.jar:2.5.0]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:438) ~[spring-boot-2.5.0.jar:2.5.0]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:337) ~[spring-boot-2.5.0.jar:2.5.0]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1336) ~[spring-boot-2.5.0.jar:2.5.0]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1325) ~[spring-boot-2.5.0.jar:2.5.0]
at zit.demo.ecommerce_springboot.ECommerceSpringBootApplication.main(ECommerceSpringBootApplication.java:10) ~[classes/:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:564) ~[na:na]
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) ~[spring-boot-devtools-2.5.0.jar:2.5.0]
Caused by: org.springframework.jdbc.datasource.init.ScriptStatementFailedException: Failed to execute SQL script statement #1 of URL [file:/C:/Dev/WorkSpaces/STS-4/ECommerce_SpringBoot/target/classes/data-h2.sql]: INSERT INTO `category` VALUES ('Jeu video'), ('Informatique'), ('Electronique'), ('Jeu de société'), ('Electroménager'), ('Littérature'), ('Multimédia'), ('Loisirs'); nested exception is org.h2.jdbc.JdbcSQLSyntaxErrorException: Table "CATEGORY" non trouvée
我做错了什么？
好的，我在这里找到了解决方案
By default, data.sql scripts are now run before Hibernate is initialized. This aligns the behavior of basic script-based initialization with that of Flyway and Liquibase. If you want to use data.sql to populate a schema created by Hibernate, set spring.jpa.defer-datasource-initialization to true.
通过在 application.properties 文件中添加 spring.jpa.defer-datasource-initialization=true 解决了问题。
对于 Spring 引导 2.4X 和更高版本，事情已经改变了一点。
data.sql脚本在 hibernate 初始化之前运行。这意味着如果你在 class-path 中有这个文件并且你没有已经创建的模式，那么 Spring 错误说schema不存在。正如许多其他人的回答，我们可以在下面使用 属性 在休眠已经创建模式后推迟初始化。
spring.jpa.defer-datasource-initialization=true以上添加完成了内存数据库的工作。但是，如果您使用其他数据库，如 PostGresSql 或 mysql，您还必须在 属性 下面添加。
spring:
sql:
init:
mode: always