Question

我尝试使用JPA，EJB和REST服务创建一个示例项目。服务运行良好，我可以发送Post和GET个请求。当我尝试通过EJB连接插入简单对象时，我得到了表未找到错误。我尝试手动创建表，但它没有工作tr

这是我的实体类

员工

@Entity
@Table(name = "employee")
public class Employee implements Serializable {

    @Id
    @Column(name = "emp_id")
    private int empId;

    @Basic(optional = false)
    @Column(name = "name", nullable = false, length = 63)
    private String name;

    @Basic(optional = false)
    @Column(name = "email", nullable = false, length = 255)
    private String email;

    @Basic(optional = false)
    @Column(name = "salary", columnDefinition = "integer default 2500")
    private int salary;

}

的persistence.xml

<?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="EmployeePU" transaction-type="JTA">
        <class>com.ams.company.Entity.Employee</class>
        <properties>
            <property name="javax.persistence.jdbc.driver" value="org.apache.derby.jdbc.EmbeddedDriver" />
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/company" />
            <property name="javax.persistence.jdbc.user" value="root" />
            <property name="javax.persistence.jdbc.password" value="" />

            <property name="eclipselink.ddl-generation" value="create-tables" />
            <property name="eclipselink.ddl-generation.output-mode"
                value="database" />
            <property name="eclipselink.ddl-generation-mode" value="ddl_database_generation" />
        </properties>

    </persistence-unit>
</persistence>

EmployeeManager

@Stateless
public class EmployeeManager {
    @PersistenceContext(unitName = "EmployeePU")
    private EntityManager entityManager;

    public EmployeeManager() {
    }

    @TransactionAttribute(TransactionAttributeType.REQUIRED)
    public boolean addEmployee(Employee employee) {
        entityManager.persist(employee);

        return true;
    }
}

Answer 1

基于以上评论的解决方案：

连接到MySQL服务器时，必须使用MySQL JDBC driver。

您不能将JDBC驱动程序用于任何其他品牌的数据库（本例中的问题是使用Apache Derby JDBC驱动程序）。

使用MySQL数据库的JPA中找不到表

1 个答案: