如何修复列"id"中的“空值"违反非空约束''

本文介绍了如何修复列"id"中的“空值"违反非空约束''的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我创建了spring mvc项目，我想使用Hibernate(v5)将模型类添加到DB(postgres v10)中，但是当执行程序时，显示错误"id"列中的空值违反了-null约束"

I'm created spring mvc project ,and i want to added model class in to DB(postgres v10) with Hibernate(v5) but when execute program, show error "null value in column "id" violates not-null constraint"

我在下面显示代码的重要部分

I show the important parts of the code in below

@Entity @Table(name = "trs") public class infoExcel { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Integer id; private Integer rule_id; private String device_id; private String ts_date; private String ts_time; private String op_type; private String detail_pay; private String card_num; private String ref_num; private String tr_code; private String price; private String month_code; private Long tr_comm; public infoExcel() { } public infoExcel(String device_id, String ts_date, String ts_time, String op_type, String detail_pay, String card_num, String ref_num, String tr_code, String price, String month_code, Long tr_comm) { this.device_id = device_id; this.ts_date = ts_date; this.ts_time = ts_time; this.op_type = op_type; this.detail_pay = detail_pay; this.card_num = card_num; this.ref_num = ref_num; this.tr_code = tr_code; this.price = price; this.month_code = month_code; this.tr_comm = tr_comm; } public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public Integer getRule_id() { return rule_id; } public void setRule_id(Integer rule_id) { this.rule_id = rule_id; } public String getDevice_id() { return device_id; } public void setDevice_id(String device_id) { this.device_id = device_id; } public String getTs_date() { return ts_date; } public void setTs_date(String ts_date) { this.ts_date = ts_date; } public String getTs_time() { return ts_time; } public void setTs_time(String ts_time) { this.ts_time = ts_time; } public String getOpr_type() { return op_type; } public void setOpr_type(String opr_type) { this.op_type = opr_type; } public String getDetail_pay() { return detail_pay; } public void setDetail_pay(String detail_pay) { this.detail_pay = detail_pay; } public String getCard_number() { return card_num; } public void setCard_number(String card_number) { this.card_num = card_number; } public String getReference_number() { return ref_num; } public void setReference_number(String reference_number) { this.ref_num = reference_number; } public String getTs_code() { return tr_code; } public void setTs_code(String ts_code) { this.tr_code = ts_code; } public String getPrice() { return price; } public void setPrice(String price) { this.price = price; } public String getMonth_code() { return month_code; } public void setMonth_code(String month_code) { this.month_code = month_code; } public Long getTs_com() { return tr_comm; } public void setTs_com(Long ts_com) { this.tr_comm = ts_com; } @Override public String toString() { return "infoExcel{" + "device_id='" + device_id + '\'' + ", ts_date='" + ts_date + '\'' + ", ts_time='" + ts_time + '\'' + ", opr_type='" + op_type + '\'' + ", card_number='" + card_num + '\'' + ", reference_number='" + ref_num + '\'' + ", ts_code='" + tr_code + '\'' + ", price='" + price + '\'' + ", month_code=" + month_code + ", ts_com=" + tr_comm + '}'; }

以及如下所示的dispatcher-servlet.xml和application-context.xml

and dispatcher-servlet.xml and application-context.xml shown below

<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="www.springframework/schema/beans" xmlns:xsi="www.w3/2001/XMLSchema-instance" xmlns:context="www.springframework/schema/context" xmlns:mvc="www.springframework/schema/mvc" xmlns:tx="www.springframework/schema/mvc" xsi:schemaLocation="www.springframework/schema/beans www.springframework/schema/beans/spring-beans.xsd www.springframework/schema/context www.springframework/schema/context/spring-context.xsd www.springframework/schema/mvc www.springframework/schema/mvc/spring-mvc.xsd"> <context:component-scan base-package="com.dsr"/> <mvc:annotation-driven /> <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/views/"/> <property name="suffix" value=".jsp"/> </bean> <mvc:resources mapping="/resources/**" location="/WEB-INF/resources/" /> <!-- File Upload Configuration Bean Details --> <bean id="multipartResolver" class="org.springframework.web.multipartmons.CommonsMultipartResolver"> <property name="maxUploadSize" value="10000000000000"/> </bean> <tx:annotation-driven/> </beans>

和应用程序上下文是

<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="www.springframework/schema/beans" xmlns:xsi="www.w3/2001/XMLSchema-instance" xsi:schemaLocation="www.springframework/schema/beans www.springframework/schema/beans/spring-beans.xsd"> <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName" value="org.postgresql.Driver"/> <property name="url" value="jdbc:postgresql://localhost:5432/dsr"/> <property name="username" value="postgres"/> <property name="password" value="123"/> </bean> <bean id="sessionFactory" class="org.springframework.orm.hibernate5.LocalSessionFactoryBean"> <property name="dataSource" ref="dataSource"/> <property name="hibernateProperties"> <props> <prop key="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</prop> <prop key="hibernate.hbm2ddl.auto">update</prop> <prop key="hibernate.show_sql">true</prop> <prop key="hibernate.format_sql">true</prop> </props> </property> <property name="packagesToScan"> <list> <value>com.dsr</value> </list> </property> </bean> <bean id="transactionManager" class="org.springframework.orm.hibernate5.HibernateTransactionManager"> <property name="sessionFactory" ref="sessionFactory"/> </bean> <bean id="multipartResolver" class="org.springframework.web.multipartmons.CommonsMultipartResolver"> <property name="maxUploadSize" value="10240000"/> </bean> </beans>

我的存储库是

@Repository @Transactional public class FileUploadDaoImpl implements FileUploadDao { @Autowired private SessionFactory sessionFactory; Session session; public void addExcel(infoExcel infoExcel) { try { session = sessionFactory.getCurrentSession(); } catch (HibernateException e) { session = sessionFactory.openSession(); } session.saveOrUpdate(infoExcel); session.flush(); } }

推荐答案

我将其用于在PostgreSQL中创建序列生成器.我正在使用Long，但是我认为使用Integer时，此代码也可以工作.

I use this for create sequence generator in PostgreSQL. I`m using Long, but I think with Integer this code work too.

@Id @GeneratedValue( strategy = GenerationType.SEQUENCE, generator = "entity_id_seq" ) @SequenceGenerator( name = "entity_id_seq", sequenceName = "global_id_sequence", allocationSize = 1 ) @Column( name = "id", unique = true, updatable = false, nullable = false ) protected Long id;