javax.jdo.JDOUserException:持久类;“聊天用户”;数据库中没有表

javax.jdo.JDOUserException:持久类;“聊天用户”;数据库中没有表,java,jdo,datanucleus,Java,Jdo,Datanucleus,我正在从h2数据库中检索数据。我的问题在q.setClass()中。 这里我试图设置表chatUsers.class,数据库有相同的类,但这表明没有表chatUsers。那么我能做些什么呢 如果我不写q.setClass()。然后它会给出数据,但问题是我无法得到那个类的列表 聊天用户类 import javax.jdo.JDOHelper; import javax.jdo.PersistenceManager; import javax.jdo.PersistenceManagerFactor

我正在从h2数据库中检索数据。我的问题在q.setClass()中。 这里我试图设置表chatUsers.class,数据库有相同的类,但这表明没有表chatUsers。那么我能做些什么呢

如果我不写q.setClass()。然后它会给出数据,但问题是我无法得到那个类的列表

聊天用户类

import javax.jdo.JDOHelper;
import javax.jdo.PersistenceManager;
import javax.jdo.PersistenceManagerFactory;
import javax.jdo.Query;
import javax.jdo.annotations.IdGeneratorStrategy;
import javax.jdo.annotations.PersistenceCapable;
import javax.jdo.annotations.Persistent;
import javax.jdo.annotations.PrimaryKey;
import java.util.List;
import java.util.Properties;

@PersistenceCapable(detachable="true")
public class ChatUsers {

    @PrimaryKey
    @Persistent(valueStrategy = IdGeneratorStrategy.INCREMENT)
    int id;
    String user;
    String mobileNo;
    String email;
    String password;

    public ChatUsers(String user, String password, String mobileNo, String email) {
        this.user = user;
        this.mobileNo = mobileNo;
        this.email = email;
        this.password = password;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getUser() {
        return user;
    }

    public void setUser(String user) {
        this.user = user;
    }

    public String getMobileNo() {
        return mobileNo;
    }

    public void setMobileNo(String mobileNo) {
        this.mobileNo = mobileNo;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
}
检索逻辑

public static List<ChatUsers> getAllUsersList() {
        PersistenceManagerFactory pmf = JDOHelper.getPersistenceManagerFactory(setProperties());
        PersistenceManager pm = pmf.getPersistenceManager();
        List<ChatUsers> chatUsersList = null;
        pm.currentTransaction().begin();
        try {
            Query q = pm.newQuery("javax.jdo.query.SQL","SELECT * FROM `CHATUSERS`");
            q.setClass(ChatUsers.class);//This line has error
             chatUsersList = (List<ChatUsers>) q.execute();
        }catch (Exception ex)
        {
            System.out.println(ex);
        }

        return chatUsersList;
    }
在执行()查询时,应该使用executeList()。[1]

另一种解决方案可能是使用setResultClass()而不是setClass()。[1]

第一种解决方案的一个例子是:

    Query query = pm.newQuery("javax.jdo.query.SQL", "SELECT MY_ID, MY_NAME FROM MYTABLE");
query.setClass(MyClass.class);
List<MyClass> results = query.executeList();
Query Query=pm.newQuery(“javax.jdo.Query.SQL”,“从MYTABLE中选择MY_ID、MY_名称”);
query.setClass(MyClass.class);
列表结果=query.executeList();
[1] 搜索“设置候选类” 和“定义结果类型” “在文档URL中:

    Query query = pm.newQuery("javax.jdo.query.SQL", "SELECT MY_ID, MY_NAME FROM MYTABLE");
query.setClass(MyClass.class);
List<MyClass> results = query.executeList();