我已经使用 PartitionKey 注释声明了主键，但仍然得到 Entity Order 没有声明主键

Question

我有以下 POJO：

@Entity
public class Order {    
    
    @Column(name = "id")
    @PartitionKey
    private String id;

    @Column(name = "customer_id")
    private String customerId;

    @Column(name = "loyalty_id")
    private String loyaltyId;

    @Column(name = "customer_email")
    private String customerEmail;

    public Order() {

    }
    public String getId() {
       return id;
    }

    public void setId(String id) {
        this.id = id;
    }
    ... getters and setters
}

在以下代码中获取异常：

            CqlSession session = CqlSession.builder().build();
            OrderMapper mapper = new OrderMapperBuilder(session).build();
            orderDao = mapper.orderDao(CqlIdentifier.fromCql(connectionManager.getSession().getLoggedKeyspace()));

connectionManager的定义在这里：https://pastebin.com/b3GKJuV6

例外情况如下：

    Entity Order does not declare a primary key
    com.datastax.oss.driver.api.mapper.MapperException: Entity Order does not declare a primary key
        at com.datastax.oss.driver.api.mapper.MapperException.copy(MapperException.java:44)
        at com.datastax.oss.driver.internal.core.util.concurrent.CompletableFutures.getUninterruptibly(CompletableFutures.java:149)
    ...

我正在按照此处的文档进行实施：https://docs.datastax.com/en/developer/java-driver/4.2/manual/mapper/。这可能是什么原因？

编辑：- 添加架构定义：

    CREATE TABLE order_keyspace.order (
        id text PRIMARY KEY,
        customer_email text,
        customer_id text,
        loyalty_id text
    ) WITH bloom_filter_fp_chance = 0.01
        AND caching = {'keys': 'ALL', 'rows_per_partition': 'NONE'}
        AND comment = ''
        AND compaction = {'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy', 'max_threshold': '32', 'min_threshold': '4'}
        AND compression = {'chunk_length_in_kb': '64', 'class': 'org.apache.cassandra.io.compress.LZ4Compressor'}
        AND crc_check_chance = 1.0
        AND dclocal_read_repair_chance = 0.1
        AND default_time_to_live = 0
        AND gc_grace_seconds = 864000
        AND max_index_interval = 2048
        AND memtable_flush_period_in_ms = 0
        AND min_index_interval = 128
        AND read_repair_chance = 0.0
        AND speculative_retry = '99PERCENTILE';

Answer 1

完整编辑：

这里发生了一些让我感到困惑的事情，我可以重现错误的唯一方法是破坏 getter/setter，这在您的代码中似乎没有错，但是有一些复制/粘贴正在发生的转换。到目前为止，我可以看到如下：

• @Column(name = "id") 的使用 - 这不是来自 com.datastax.oss.driver.api.mapper.annotations 的注释。应该使用@CqlName。
• 对表使用保留关键字 - 术语“订单”是保留关键字，我很确定这会在代码中造成相当大的混乱 - 尽管当我尝试将关键字用作映射器的表名。我认为您应该将此表命名为其他名称并避免使用关键字。

注释链接： https://docs.datastax.com/en/developer/java-driver/4.2/manual/mapper/entities/ 包含可用的规则/注释，如果与命名约定不同，您可以看到 @CqlName 的使用通知映射器 Cassandra 列名称。

我相信您在之前的问题中使用的是 4.2 驱动程序 - 但如果更新到 4.7（推荐），那么这是链接：https://docs.datastax.com/en/developer/java-driver/4.7/manual/mapper/entities/）

以下代码运行正常：

Cql：

CREATE TABLE customer_orders (
    id text PRIMARY KEY,
    customer_email text,
    customer_id text,
    loyalty_id text
);

insert into customer_orders (id, customer_email, customer_id, loyalty_id) values ('a','a@b.c.com', '1234', '5678');

波乔：

import com.datastax.oss.driver.api.mapper.annotations.CqlName;
import com.datastax.oss.driver.api.mapper.annotations.Entity;
import com.datastax.oss.driver.api.mapper.annotations.PartitionKey;

@Entity
public class CustomerOrders {
    @CqlName("id")
    @PartitionKey
    private String id;

    @CqlName("customer_id")
    private String customerId;

    @CqlName("loyalty_id")
    private String loyaltyId;

    @CqlName("customer_email")
    private String customerEmail;

    public CustomerOrders() {

    }

    public String getId() {
        return id;
    }

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

    public String getCustomerId() {
        return customerId;
    }

    public void setCustomerId(String customerId) {
        this.customerId = customerId;
    }

    public String getLoyaltyId() {
        return loyaltyId;
    }

    public void setLoyaltyId(String loyaltyId) {
        this.loyaltyId = loyaltyId;
    }

    public String getCustomerEmail() {
        return customerEmail;
    }

    public void setCustomerEmail(String customerEmail) {
        this.customerEmail = customerEmail;
    }
}

道映射器：

import com.datastax.oss.driver.api.core.CqlIdentifier;
import com.datastax.oss.driver.api.mapper.annotations.*;

@Mapper
public interface DaoMapper {

    @DaoFactory
    OrderDao orderDao(@DaoKeyspace CqlIdentifier keyspace);
}

OrderDao：

import com.datastax.oss.driver.api.mapper.annotations.Dao;
import com.datastax.oss.driver.api.mapper.annotations.Delete;
import com.datastax.oss.driver.api.mapper.annotations.Insert;
import com.datastax.oss.driver.api.mapper.annotations.Select;

@Dao
public interface OrderDao {

    @Select
    CustomerOrders findById(String id);

    @Insert
    void save(CustomerOrders order);

    @Delete
    void delete(CustomerOrders order);
}

然后我创建了一个简单的测试sn-p：

 @Test
    void GetRecordViaOrderDao() {
        try (CqlSession session = CqlSession.builder().build()) {

            DaoMapper daoMapper = new DaoMapperBuilder(session).build();
            OrderDao orderDao = daoMapper.orderDao(CqlIdentifier.fromCql("killrvideo"));
            CustomerOrders order = orderDao.findById("a");
            System.out.println(order.getCustomerEmail());
        }
    }

在这种情况下，killrvideo 键空间，因为我正在访问 Astra DB，这就是我目前拥有的键空间。

Result: a@b.c.com

驱动程序版本 4.7.2 在我的 pom.xml 中指定

Answer 2

@Andrew 谢谢，我对@PartitionKey 使用了错误的导入。正确的是你提到的import com.datastax.oss.driver.api.mapper.annotations.PartitionKey;。