我在 mysql 中有 2 个表,blocked_histories
和 blocked_detail_histories
。 block_detail_histories 表与 block_histories 具有多对一的 hibernate 关系。表创建脚本如下所示
被阻止的历史记录
CREATE TABLE `blocked_histories` (
`id` INT(11) NOT NULL AUTO_INCREMENT,
`type` VARCHAR(32) NOT NULL,
`no_ecash` varchar(13) NOT NULL,
`cif` VARCHAR(32) DEFAULT NULL,
`reason_id` INT(4) NOT NULL,
`desc` TEXT,
`status` VARCHAR(32) NOT NULL,
`created_date` DATETIME NOT NULL,
`created_by` VARCHAR(100) NOT NULL,
`total_balance` DECIMAL(15,6) NOT NULL,
`broker` int(11) NOT NULL,
`blocked_id` INT(11) NOT NULL UNIQUE,
`remark` text,
PRIMARY KEY (`id`),
CONSTRAINT `CUSTOMFIELD_ID_FK` FOREIGN KEY (`reason_id`) REFERENCES `custom_field_possible_values` (`id`)
) ENGINE=INNODB AUTO_INCREMENT=312 DEFAULT CHARSET=latin1;
阻止的_详细_历史记录
CREATE TABLE `blocked_detail_histories` (
`id` INT(11) NOT NULL AUTO_INCREMENT,
`blocked_id` INT(11) NOT NULL,
`no_ecash` VARCHAR(13) DEFAULT NULL,
`prev_group` INT(11) NOT NULL,
`balance` DECIMAL(15,6) NOT NULL,
PRIMARY KEY (`id`),
KEY `BLOCKED_ID_FK` (`blocked_id`),
CONSTRAINT `BLOCKED_ID_HISTORIES_FK` FOREIGN KEY (`blocked_id`) REFERENCES `blocked_histories` (`blocked_id`)
) ENGINE=INNODB AUTO_INCREMENT=312 DEFAULT CHARSET=latin1;
hibernate 映射如下所示
被阻止的历史记录
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class dynamic-insert="true" dynamic-update="true"
name="nl.strohalm.cyclos.entities.groups.BlockedHistories"
table="blocked_histories">
<id name="id" type="long">
<column name="id" sql-type="bigint" />
<generator class="native" />
</id>
<property name="type" column="type" type="string" not-null="true" length="32" />
<property name="noEcash" column="no_ecash" type="string" not-null="true" length="13" />
<property name="cif" column="cif" type="string" length="32" />
<!-- <property name="reasonId" column="reason_id" type="int" not-null="true" length="11" /> -->
<many-to-one name="reasonId" class="nl.strohalm.cyclos.entities.customization.fields.CustomFieldPossibleValue">
<column name="reason_id" sql-type="integer"></column>
</many-to-one>
<property name="desc" column="desc" type="text" not-null="true" />
<property name="status" column="status" type="string" length="32" />
<property name="createdDate" column="created_date" type="calendar" not-null="true" />
<property name="createdBy" column="created_by" type="string" not-null="true" length="100"/>
<property name="totalBalance" column="total_balance" type="big_decimal" not-null="true" precision="15" scale="6" />
<property name="brokerId" column="broker" type="int" not-null="true" length="11" />
<property name="remark" column="remark" type="text" />
<property name="blockedId" column="blocked_id" type="int" not-null="true" length="11" />
</class>
</hibernate-mapping>
阻止的_详细_历史记录
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class dynamic-insert="true" dynamic-update="true"
name="nl.strohalm.cyclos.entities.groups.BlockedDetailHistories"
table="blocked_detail_histories">
<id name="id" type="long">
<column name="id" sql-type="bigint" />
<generator class="native" />
</id>
<many-to-one name="blockedHistories" class="nl.strohalm.cyclos.entities.groups.BlockedHistories">
<column name="blocked_id" sql-type="integer"></column>
</many-to-one>
<property name="noEcash" column="no_ecash" type="string" not-null="true" length="13" />
<property name="prevGroup" column="prev_group" type="int" not-null="true" length="11" />
<property name="balance" column="balance" type="big_decimal" not-null="true" precision="15" scale="6" />
</class>
</hibernate-mapping>
如您所见,blocked_detail 历史记录表与blocked_histories 表(在“blockedHistories”列中)具有多对一关系
我尝试运行一个简单的 mysql 查询来连接两个如下所示的表
select bh.created_date, bdh.no_ecash, bh.type,
bh.cif, bh.desc, bh.reason_id,
bh.status, bh.created_by, bh.remark
from blocked_detail_histories bdh
join blocked_histories bh
where bdh.blocked_id=4;
上面的mysql查询工作正常,但是当我尝试将上面的mysql查询转换为HQL查询时,结果没有给我任何结果..HQL看起来像这样(这里的“:id”是java NamedParameters)
select bdh.blockedHistories.blockedId
from BlockedDetailHistories bdh"
join bdh.blockedHistories bh
where bh.blockedId = :id
我尝试了这个,但也没有给我任何东西
select bh.createdDate, bdh.noEcash, bh.type,
bh.cif, bh.desc, bh.reasonId,
bh.status, bh.createdBy, bh.remark
from BlockedDetailHistories bdh
join bdh.blockedHistories bh
where bh.blockedId = :id
我在这里缺少什么建议吗?关系定义也许?或者其他什么?任何帮助将不胜感激:)
最佳答案
不是 xml hibernate 映射方面的专家, 但是您是否为 hibernate 实体类应用了 fetch 类型, 如果您定义了这样的内容,那么您可以按如下方式重试上面的查询(如果是延迟获取类型)
select bdh.blockedHistories.blockedId
from BlockedDetailHistories bdh
left join fetch bdh.blockedHistories bh
where bh.blockedId = :id
关于java - Hibernate HQL 多对一连接,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/40850301/