在內存數據庫中使用Hibernate與H2一起使用時出錯

Question

我正在使用Hibernate。我如何配置我的persistence.xml以擁有H2內存數據庫？

我的persistence.xml是：

<?xml version="1.0" encoding="UTF-8" ?> 
<persistence xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd" 
    version="2.0" xmlns="http://java.sun.com/xml/ns/persistence"> 
    <persistence-unit name="persistenceUnit" 
     transaction-type="RESOURCE_LOCAL"> 

     <class>com.mastertheboss.domain.Employee</class> 
     <class>com.mastertheboss.domain.Department</class> 
     <properties> 

      <property name="javax.persistence.jdbc.driver" value="org.h2.Driver" /> 
      <property name="javax.persistence.jdbc.url" value="jdbc:h2:mem:test;DB_CLOSE_DELAY=-1" /> 
      <property name="javax.persistence.jdbc.user" value="sa" /> 
      <property name="javax.persistence.jdbc.password" value="" /> 
      <property name="hbm2ddl.auto" value="update" /> 

      <property name="hibernate.dialect" value="org.hibernate.dialect.H2Dialect" /> 
     </properties> 

    </persistence-unit> 
</persistence> 

但是當我運行我的應用程序，我得到以下錯誤：

Internal Exception: org.h2.jdbc.JdbcSQLException: Table "EMPLOYEE" not found; SQL statement: SELECT ID, NAME, DEPARTMENT_ID FROM EMPLOYEE [42102-171] Error Code: 42102 Call: SELECT ID, NAME, DEPARTMENT_ID FROM EMPLOYEE Query: ReadAllQuery(referenceClass=Employee sql="SELECT ID, NAME, DEPARTMENT_ID FROM EMPLOYEE")

Answer 1

您應該設置hibernate.hbm2ddl.auto財產來「創造」你第一次運行你的應用程序，創建表格

<property name="hibernate.hbm2ddl.auto" value="create" /> 

然後（如果您不希望每次啓動時都重新創建並清空表）將其設置爲「驗證」。

​​

要自動創建模式，加上如果 - 不 - 存在於這樣的連接網址：

<property name="hibernate.connection.url" value="jdbc:h2:~/<filename>;INIT=CREATE SCHEMA IF NOT EXISTS <schema_name>" />