JPA：MySQL说表不存在，但实际上它是存在的

Question

我有以下脚本来创建表autolife.log:

CREATE TABLE `log` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `idpoint` int(11) NOT NULL,
  `value` varchar(10) NOT NULL,
  `time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  KEY `fk_point_id` (`idpoint`),
  CONSTRAINT `fk_point_id` FOREIGN KEY (`idpoint`) REFERENCES `point` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=InnoDB AUTO_INCREMENT=155562 DEFAULT CHARSET=latin2$$

我使用 JPA 工具 在 Eclipse Indigo 中从表格创建实体：

@Entity
public class Log implements Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    @SequenceGenerator(name="LOG_ID_GENERATOR", sequenceName="SEQUENCE_KEY")
    @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="LOG_ID_GENERATOR")
    private Integer id;

    private Timestamp time;

    private String value;

    //bi-directional many-to-one association to Point
    @ManyToOne
    @JoinColumn(name="idpoint")
    private Point point;

    public Log() {
    }

    // get's and set's

当我在本地计算机上运行时，一切正常，但是当我导出.war并放到生产环境中时，会出现以下错误（下面可以看到代码生成的异常）：

ubuntu@domU-12-31-39-0A-12-7B:~/glassfish/glassfish3/glassfish/domains/domain1/logs$ vi server.log
        at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeCall(DatasourceCallQueryMechanism.java:193)
        at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeSelectCall(DatasourceCallQueryMechanism.java:264)
        at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.selectAllRows(DatasourceCallQueryMechanism.java:646)
        at org.eclipse.persistence.internal.queries.ExpressionQueryMechanism.selectAllRowsFromTable(ExpressionQueryMechanism.java:2611)
        at org.eclipse.persistence.internal.queries.ExpressionQueryMechanism.selectAllRows(ExpressionQueryMechanism.java:2570)
        at org.eclipse.persistence.queries.ReadAllQuery.executeObjectLevelReadQuery(ReadAllQuery.java:420)
        at org.eclipse.persistence.queries.ObjectLevelReadQuery.executeDatabaseQuery(ObjectLevelReadQuery.java:1081)
        at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:844)
        at org.eclipse.persistence.queries.ObjectLevelReadQuery.execute(ObjectLevelReadQuery.java:1040)
        at org.eclipse.persistence.queries.ReadAllQuery.execute(ReadAllQuery.java:392)
        at org.eclipse.persistence.queries.ObjectLevelReadQuery.executeInUnitOfWork(ObjectLevelReadQuery.java:1128)
        at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.internalExecuteQuery(UnitOfWorkImpl.java:2871)
        at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1516)
        at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1498)
        at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1463)
        at org.eclipse.persistence.internal.jpa.EJBQueryImpl.executeReadQuery(EJBQueryImpl.java:485)
        at org.eclipse.persistence.internal.jpa.EJBQueryImpl.getResultList(EJBQueryImpl.java:742)
        at com.brainset.eao.LogEAO.list(LogEAO.java:54)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.glassfish.ejb.security.application.EJBSecurityManager.runMethod(EJBSecurityManager.java:1052)
        at org.glassfish.ejb.security.application.EJBSecurityManager.invoke(EJBSecurityManager.java:1124)
        at com.sun.ejb.containers.BaseContainer.invokeBeanMethod(BaseContainer.java:5388)
        at com.sun.ejb.EjbInvocation.invokeBeanMethod(EjbInvocation.java:619)
        at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:800)
        at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:571)
        at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.doAround(SystemInterceptorProxy.java:162)
        at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.aroundInvoke(SystemInterceptorProxy.java:144)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:861)
        at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:800)
        at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:370)
        at com.sun.ejb.containers.BaseContainer.__intercept(BaseContainer.java:5360)
        at com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:5348)
        at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:214)
        ... 44 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'autolife.LOG' doesn't exist
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
        at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
        at com.mysql.jdbc.Util.getInstance(Util.java:386)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1052)
        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4098)
        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4030)
        at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2490)
        at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2651)
        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2677)
        at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2134)
        at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:2300)
        at com.sun.gjc.spi.jdbc40.PreparedStatementWrapper40.executeQuery(PreparedStatementWrapper40.java:642)
        at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeSelect(DatabaseAccessor.java:931)
        at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.basicExecuteCall(DatabaseAccessor.java:607)
        ... 88 more
|#]

正如您所看到的，它说表不存在，但是我从本地主机数据库导出并导入到生产主机中。 但仍然出现此错误：

Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'autolife.LOG' doesn't exist

我应该在这里做什么？

- Valter Silva

Answer 1

MySQL表名的大小写敏感性取决于操作系统，我想这就是原因:

在MySQL中，数据库对应数据目录中的目录。每个数据库中的每个表对应于数据库目录中至少一个文件(根据存储引擎可能还有更多)。因此，底层操作系统的大小写敏感性在数据库和表名称的大小写敏感性中起着一定作用。这意味着，在Windows中，数据库和表名称不区分大小写，在大多数Unix变体中区分大小写。一个显著的例外是Mac OS X，它是基于Unix的，但使用默认的文件系统类型(HFS+)不区分大小写。然而，Mac OS X也支持UFS卷，它们像任何Unix那样区分大小写。

因此，您需要明确以正确的大小写设置表名：

@Entity @Table(name = "log")
public class Log implements Serializable { ... }

- axtavt

Answer 2

很酷的问题。 关于什么？

USE <Database Name>
GO

在执行脚本之前需要添加哪些语句？

通常在执行存储过程和表格之前都需要添加这两行语句。

- Siarhei Kuchuk

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这个看起来不太像Java风格的代码？ - phil294