休眠一对多关联错误

Question

Hi im new to hibernate. I m not able to figure out why entries are not updated in my database... My application have 3 entities: Contracts, Bank, Contractor.

Each contract is associated with only one contractor and bank.

A contractor or bank can have multiple contracts.

Contract.java

private String contractId;
private Contract contractor
private Bank bank;

Contractor.java

private long contractorId;
private Set<Contract> contracts

Bank.java

private bankId;
private Set<Contract> contracts;

Hibernate.hbm.cfg

<class name="com.anksys.bgms.model.Contractor" table="BGMS_CONTRACTOR">
    <id name="contractorId" column="CONTRACTOR_ID" type="long">
        <generator class="identity"></generator>
    </id>
    <set name="contracts" table="BGMS_CONTRACT" inverse="true" lazy="true">
        <key>
            <column name="CONTRACT_ID" not-null="true"></column>
        </key>
        <one-to-many class="com.anksys.bgms.model.Contract"/>
    </set>
</class>
<class name="com.anksys.bgms.model.Bank" table="BGMS_BANK">
    <id name="bankId" column="BANK_ID" type="long">
        <generator class="identity"></generator>
    </id>
    <set name="contracts" table="BGMS_CONTRACT" lazy="true">
        <key>
            <column name="CONTRACT_ID" not-null="true"></column>
        </key>
        <one-to-many class="com.anksys.bgms.model.Contract"/>
    </set>
</class>

<class name="com.anksys.bgms.model.Contract" table="BGMS_CONTRACT">
    <id name="contractId" column="CONTRACT_ID" type="string"></id>
    <many-to-one name="contractor" class="com.anksys.bgms.model.Contractor"></many-to-one>
    <many-to-one name="bank" class="com.anksys.bgms.model.Bank"></many-to-one>
</class>

DATABASE Structure:

bgms_bank: 
BANK_ID     bigint(20)  No      
Index: PRIMARY  BTREE   Yes No  CONTRACTOR_ID   4   A   No

bgms_contract:
CONTRACT_ID     varchar(50)     No      
CONTRACTOR_ID   bigint(20)  No      
BANK_ID     bigint(20)  No  
INDEX: 
Contract.contractor_id references(contractor.contractor_ID)
Contract.Bank_ID references(bank.BANK_ID)

bgms_contractor:
CONTRACTOR_ID   bigint(20)  No
INDEX: PRIMARY  BTREE   Yes No  CONTRACTOR_ID           

At the end: receiving this: org.springframework.dao.InvalidDataAccessResourceUsageException: Could not execute JDBC batch update; SQL [insert into BGMS_CONTRACT (GUARANTEE_AMOUNT, VALID_FROM, VALID_UPTO, EXTENDED_UPTO, contractor, bank, CONTRACT_ID) values (?, ?, ?, ?, ?, ?, ?)]; nested exception is org.hibernate.exception.SQLGrammarException: Could not execute JDBC batch update org.springframework.dao.InvalidDataAccessResourceUsageException: Could not execute JDBC batch update; SQL [insert into BGMS_CONTRACT (GUARANTEE_AMOUNT, VALID_FROM, VALID_UPTO, EXTENDED_UPTO, contractor, bank, CONTRACT_ID) values (?, ?, ?, ?, ?, ?, ?)]; nested exception is org.hibernate.exception.SQLGrammarException: Could not execute JDBC batch update

Caused by: java.sql.BatchUpdateException: Unknown column 'contractor' in 'field list'

Answer 1

Try this:

<class name="com.anksys.bgms.model.Contract" table="BGMS_CONTRACT">
    <id name="contractId" column="CONTRACT_ID" type="string"></id>
    <many-to-one name="contractor" class="com.anksys.bgms.model.Contractor" column="contractor_id"></many-to-one>
    <many-to-one name="bank" class="com.anksys.bgms.model.Bank" column="bank_id"></many-to-one>
</class>

I've added column attribute to <many-to-one> tag