Question

我是hibernate的新手，我正在尝试使用xml中的映射示例。我在运行应用程序时遇到上述错误请帮忙。这是我写的代码

这是映射类

quotation.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
    <class name="main.com.paramatrix.models.Quotation" table="quotation">
        <id name="quotationId" type="long">
            <column name="QUOTATION_ID" />
            <generator class="identity" />
        </id>
        <property column="NO_OF_ITEMS" name="noOfItems" type="long" />
        <property column="QUOTATION_GEN_DATE" name="quotationGenDate"
            type="string" />
        <one-to-one name="invoice" class="main.com.paramatrix.models.Invoice"
            cascade="save-update"></one-to-one>

        <set name="itemList" table="item" inverse="true" lazy="true"
            fetch="select">
            <key>
                <column name="QUOTATION_ID" not-null="true" />
            </key>
            <one-to-many class="main.com.paramatrix.models.Item" />
        </set>


        <many-to-one name="user" class="main.com.paramatrix.models.User"
            fetch="select">
            <column name="USER_ID" not-null="true" />
        </many-to-one>

    </class>
</hibernate-mapping>

user.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
    <class name="main.com.paramatrix.models.User" table="user">
        <id name="userId" type="long">
            <column name="USER_ID" />
            <generator class="identity" />
        </id>
        <property column="USER_NAME" name="userName" type="string" />

        <set name="quotationList" table="quotation" inverse="true" lazy="true"
            fetch="select">
            <key>
                <column name="USER_ID" not-null="true" />
            </key>
            <one-to-many class="main.com.paramatrix.models.Quotation" />
        </set>
    </class>
</hibernate-mapping>

以下是我用于映射的POJO类

User.java

public class User implements Serializable{

    private long userId ;
    private String userName;
    private Set<Quotation> quotationList = new HashSet<Quotation>();
    public long getUserId() {
        return userId;
    }
    public void setUserId(long userId) {
        this.userId = userId;
    }
    public String getUserName() {
        return userName;
    }
    public void setUserName(String userName) {
        this.userName = userName;
    }
    public Set<Quotation> getQuotationList() {
        return quotationList;
    }
    public void setQuotationList(Set<Quotation> quotationList) {
        this.quotationList = quotationList;
    }

}


Quotation.java

    public class Quotation implements Serializable{

        private long quotationId;
        private long noOfItems;
        private String quotationGenDate;
        private Set<Item> itemList = new HashSet<Item>();
        private Invoice invoice;
        private User user;
        public long getQuotationId() {
            return quotationId;
        }
        public void setQuotationId(long quotationId) {
            this.quotationId = quotationId;
        }
        public long getNoOfItems() {
            return noOfItems;
        }
        public void setNoOfItems(long noOfItems) {
            this.noOfItems = noOfItems;
        }
        public String getQuotationGenDate() {
            return quotationGenDate;
        }
        public void setQuotationGenDate(String quotationGenDate) {
            this.quotationGenDate = quotationGenDate;
        }
        public Set<Item> getItemList() {
            return itemList;
        }
        public void setItemList(Set<Item> itemList) {
            this.itemList = itemList;
        }
        public Invoice getInvoice() {
            return invoice;
        }
        public void setInvoice(Invoice invoice) {
            this.invoice = invoice;
        }
        public User getUser() {


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


        }
App.js
public class App {

    public static void main(String args[]) {
        User user = new User();
        user.setUserName("Pradip");

        Quotation quotation = new Quotation();
        Item item1 = new Item();
        item1.setItemName("laptop");
        Item item2 = new Item();
        item2.setItemName("mobile");
        // Set<Item> itemList = new HashSet<>();

        // itemList.add(item1);
        // itemList.add(item2);

        // quotation.setNoOfItems(itemList.size());
        quotation.setUser(user);
        quotation.getItemList().add(item1);
        quotation.getItemList().add(item2);
        quotation.setNoOfItems(quotation.getItemList().size());

        Invoice invoice = new Invoice();
        invoice.setInvoiceGenDate("13-10-2017");
        invoice.setTotalBill(50000);
        quotation.setInvoice(invoice);
        invoice.setQuotation(quotation);
        // Set<Quotation> quotationos = new HashSet<Quotation>();
        // quotationos.add(quotation);
        user.getQuotationList().add(quotation);

        DataProvider.addData(main.com.paramatrix.models.User.class, user);

        DataProvider.addData(main.com.paramatrix.models.Quotation.class, quotation);

        DataProvider.addData(main.com.paramatrix.models.Invoice.class, invoice);

    }

提前感谢！

这是错误消息

无法添加或更新子行：外键约束失败（hibernate_assign。quotation，CONSTRAINT FKA771958CD5030893 FOREIGN KEY（USER_ID）REFERENCES user（USER_ID））例外情况线程＆＃34;主要＆＃34; org.hibernate.exception.ConstraintViolationException：无法插入：[main.com.paramatrix.models.Quotation] at org.hibernate.exception.SQLStateConverter.convert（SQLStateConverter.java:96）在 org.hibernate.exception.JDBCExceptionHelper.convert（JDBCExceptionHelper.java:66）在 org.hibernate.id.insert.AbstractReturningDelegate.performInsert（AbstractReturningDelegate.java:63）在 org.hibernate.persister.entity.AbstractEntityPersister.insert（AbstractEntityPersister.java:2346）在 org.hibernate.persister.entity.AbstractEntityPersister.insert（AbstractEntityPersister.java:2853）在 org.hibernate.action.EntityIdentityInsertAction.execute（EntityIdentityInsertAction.java:71）在org.hibernate.engine.ActionQueue.execute（ActionQueue.java:273）at at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate（AbstractSaveEventListener.java:320）在 org.hibernate.event.def.AbstractSaveEventListener.performSave（AbstractSaveEventListener.java:203）在 org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId（AbstractSaveEventListener.java:129）在 org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId（DefaultSaveOrUpdateEventListener.java:210）在 org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId（DefaultSaveEventListener.java:56）在 org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient（DefaultSaveOrUpdateEventListener.java:195）在 org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate（DefaultSaveEventListener.java:50）在 org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate（DefaultSaveOrUpdateEventListener.java:93）在org.hibernate.impl.SessionImpl.fireSave（SessionImpl.java:713）at org.hibernate.impl.SessionImpl.save（SessionImpl.java:701）at org.hibernate.impl.SessionImpl.save（SessionImpl.java:697）at main.com.paramatrix.util.DataProvider.addData（DataProvider.java:10）在main.com.paramatrix.util.App.main（App.java:49）引起： com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException：无法添加或更新子行：外键约束失败（hibernate_assign。quotation，CONSTRAINT FKA771958CD5030893 FOREIGN KEY（USER_ID）引用user（USER_ID））at sun.reflect.NativeConstructorAccessorImpl.newInstance0（本机方法） at sun.reflect.NativeConstructorAccessorImpl.newInstance（未知来源）at sun.reflect.DelegatingConstructorAccessorImpl.newInstance（未知来自java.lang.reflect.Constructor.newInstance（未知来源）在com.mysql.jdbc.Util.handleNewInstance（Util.java:425）at com.mysql.jdbc.Util.getInstance（Util.java:408）at com.mysql.jdbc.SQLError.createSQLException（SQLError.java:935）at at com.mysql.jdbc.MysqlIO.checkErrorPacket（MysqlIO.java:3973）at at com.mysql.jdbc.MysqlIO.checkErrorPacket（MysqlIO.java:3909）at at com.mysql.jdbc.MysqlIO.sendCommand（MysqlIO.java:2527）at at com.mysql.jdbc.MysqlIO.sqlQueryDirect（MysqlIO.java:2680）at at com.mysql.jdbc.ConnectionImpl.execSQL（ConnectionImpl.java:2501）at at com.mysql.jdbc.PreparedStatement.executeInternal（PreparedStatement.java:1858）在 com.mysql.jdbc.PreparedStatement.executeUpdateInternal（PreparedStatement.java:2079）在 com.mysql.jdbc.PreparedStatement.executeUpdateInternal（PreparedStatement.java:2013）在 com.mysql.jdbc.PreparedStatement.executeLargeUpdate（PreparedStatement.java:5104）在 com.mysql.jdbc.PreparedStatement.executeUpdate（PreparedStatement.java:1998）在 org.hibernate.id.IdentityGenerator $ GetGeneratedKeysDelegate.executeAndExtract（IdentityGenerator.java:93）在 org.hibernate.id.insert.AbstractReturningDelegate.performInsert（AbstractReturningDelegate.java:56）

Answer 1

这是我的方法：

首先，您需要更新报价的映射文件：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
    <class name="main.com.paramatrix.models.Quotation" table="quotation">
        <id name="quotationId" type="long">
            <column name="QUOTATION_ID" />
            <generator class="identity" />
        </id>
        <property column="NO_OF_ITEMS" name="noOfItems" type="long" />
        <property column="QUOTATION_GEN_DATE" name="quotationGenDate"
            type="string" />
        <one-to-one name="invoice" class="main.com.paramatrix.models.Invoice"
            cascade="save-update"></one-to-one>

        <set name="itemList" table="item" inverse="true" lazy="true"
            fetch="select">
            <key>
                <column name="QUOTATION_ID" not-null="true" />
            </key>
            <one-to-many class="main.com.paramatrix.models.Item" />
        </set>


        <many-to-one name="user" class="main.com.paramatrix.models.User"
            fetch="select">
            <column name="USER_ID" not-null="false" />
        </many-to-one>

    </class>
</hibernate-mapping>

然后更新您的主要内容：

public static void main(String args[]) {
    User user = new User();
    user.setUserName("Pradip");

    Quotation quotation = new Quotation();
    Item item1 = new Item();
    item1.setItemName("laptop");
    Item item2 = new Item();
    item2.setItemName("mobile");
    // Set<Item> itemList = new HashSet<>();

    // itemList.add(item1);
    // itemList.add(item2);

    // quotation.setNoOfItems(itemList.size());
    quotation.setUser(user);
    quotation.getItemList().add(item1);
    quotation.getItemList().add(item2);
    quotation.setNoOfItems(quotation.getItemList().size());

    Invoice invoice = new Invoice();
    invoice.setInvoiceGenDate("13-10-2017");
    invoice.setTotalBill(50000);
    quotation.setInvoice(invoice);
    invoice.setQuotation(quotation);
  DataProvider.addData(main.com.paramatrix.models.Quotation.class, quotation);
 user.getQuotationList().add(quotation);
    DataProvider.addData(main.com.paramatrix.models.User.class, user);



    DataProvider.addData(main.com.paramatrix.models.Invoice.class, invoice);

}

修改

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <class name="main.com.paramatrix.models.User" table="user"> <id name="userId" type="long"> <column name="USER_ID" /> <generator class="identity" /> </id> <property column="USER_NAME" name="userName" type="string" /> <set name="quotationList" table="quotation" inverse="true" lazy="true" cascade="all" fetch="select"> <key> <column name="USER_ID" not-null="true" /> </key> <one-to-many class="main.com.paramatrix.models.Quotation" /> </set> </class> </hibernate-mapping>

com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException：无法添加或更新子行

1 个答案: