Question

首先，我必须将我的实体类从Employee重命名为EMPLOYEE，因为无论出于何种原因我都有错误Internal Exception: java.sql.SQLSyntaxErrorException: Table/View 'EMPLOYEE' does not exist，我正在使用这个类Employee，后来改名为EMPLOYEE

@Entity
public class Employee {

@Id
private int id;
private String name;
private long salary;

public Employee(){}
public Employee(int id){this.id=id;}

// getters, setters
}

这是持久性xml

<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
<persistence-unit name="EmployeeService" transaction-type="RESOURCE_LOCAL">
<!--<exclude-unlisted-classes>false</exclude-unlisted-classes>
-->
<class>jpa.Employee</class>
    <properties>

        <property name="javax.persistence.jdbc.driver" value="oracle.jdbc.OracleDriver"/>
        <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/jpa00"/> 
        <property name="javax.persistence.jdbc.user" value="root"/> 
        <property name="javax.persistence.jdbc.password" value="123"/>

    </properties>
</persistence-unit>
</persistence>

我正在使用一个名为jpa00的模式，其中包含一个包含3列的表Employee：主键，unsigned，not null，int id; varchar name和int salary。其余代码使用名为EmployeeServices的实用程序类

public class EmployeeTest {

public static void main (String[] args) {

    EntityManagerFactory emf =
        Persistence.createEntityManagerFactory("EmployeeService");
    EntityManager em = emf.createEntityManager();
    EmployeeService service = new EmployeeService(em);

    // create and persist an employee
    em.getTransaction().begin();
    Employee emp = service.createEmployee(158, "John Doe", 45000);
    em.getTransaction().commit();
    System.out.println("Persisted "+emp);

    // find specific employee
    emp = service.findEmployee(158);
    System.out.println("Found "+emp);

    // find all employees
    List<Employee> list = service.findAllEmployees();
    for(Employee y:list)
        System.out.println(y);

    // update the employee
    em.getTransaction().begin();
    emp = service.raiseEmployeeSalary(158, 1000);
    em.getTransaction().commit();
    System.out.println("Updated "+emp);

    // remove an employee
    em.getTransaction().begin();
    service.removeEmployee(158);
    em.getTransaction().commit();
    System.out.println("Removed employee 158");

    // close the Em and EMF when done
    em.close();
    emf.close();

}

当我将实体类从Employee更改为EMPLOYEE并且我运行它时，我有第一个操作System.out.println("Persisted "+emp);的输出，之后我有这个错误Exception in thread "main" java.lang.IllegalArgumentException: Unknown Entity bean class: class jpa.EMPLOYEE, please verify that this class has been marked with the @Entity annotation.该类有@Entity注释，所以我不知道我做错了什么。我使用NetBeans 8.1，并且已导入到库 EclipseLink JPA 2.1 和MySQL JDBC Driver中。我真的不知道我应该做什么以及所有大写的员工问题，我只是不明白这是怎么回事。

Answer 1

首先;您正尝试使用Oracle Driver连接到MySql。 Oracle和mysql有不同的驱动程序，编辑你的persistence.xml来设置mysql驱动程序

二; @Table注释可能有助于类名和表名匹配（如果您的mysql配置具有区分大小写的表名，则需要这样做）

@Entity 
@Table(name = "EMPLOYEE") 
public class Employee {

无法使jpa与glassfish和mysql一起工作

1 个答案: