java - Eclipselink 更新现有表

Question

也许我弄错了，但我虽然 JPA 能够更新现有表(模型更改添加列)但在我的情况下不起作用。

我可以在日志中看到 eclipselink 尝试创建它但由于它已经存在而失败。而不是尝试更新以添加它继续进行的列。

<property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/jwrestling"/>
<property name="javax.persistence.jdbc.password" value="password"/>
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
<property name="javax.persistence.jdbc.user" value="user"/>
<property name="eclipselink.ddl-generation" value="create-tables"/>
<property name="eclipselink.logging.logger" value="org.eclipse.persistence.logging.DefaultSessionLog"/>
<property name="eclipselink.logging.level" value="INFO"/>

这是有变化的表格(添加了在线列)

[EL Warning]: 2010-05-31 14:39:06.044--ServerSession(16053322)--Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.1.0.v20100517-r7246): org.eclipse.persistence.exceptions.DatabaseExceptionInternal Exception: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'account' already existsError Code: 1050Call: CREATE TABLE account (ID INTEGER NOT NULL, USERNAME VARCHAR(32) NOT NULL, SECURITY_KEY VARCHAR(255) NOT NULL, EMAIL VARCHAR(64) NOT NULL, STATUS VARCHAR(8) NOT NULL, TIMEDATE DATETIME NOT NULL, PASSWORD VARCHAR(255) NOT NULL, ONLINE TINYINT(1) default 0 NOT NULL, PRIMARY KEY (ID))Query: DataModifyQuery(sql="CREATE TABLE account (ID INTEGER NOT NULL, USERNAME VARCHAR(32) NOT NULL, SECURITY_KEY VARCHAR(255) NOT NULL, EMAIL VARCHAR(64) NOT NULL, STATUS VARCHAR(8) NOT NULL, TIMEDATE DATETIME NOT NULL, PASSWORD VARCHAR(255) NOT NULL, ONLINE TINYINT(1) default 0 NOT NULL, PRIMARY KEY (ID))")[EL Warning]: 2010-05-31 14:39:06.074--ServerSession(16053322)--Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.1.0.v20100517-r7246): org.eclipse.persistence.exceptions.DatabaseException

在此之后，它会继续以下操作。

我做错了什么还是一个错误？

Answer 1

从 EclipseLink 2.4 开始，您可以在持久性单元的规范中使用它:

<property name="eclipselink.ddl-generation" value="create-or-extend-tables" />