我正在学习Hibernate,在简单的演示应用程序中,遇到问题,我无法克服。只有两个表,两个实体类和主应用程序。项目在maven。
Github:github.com/fangirsan/maruszka.git
Batch.class:
package com.maruszka.entity;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
@Entity
@Table(name="batch")
public class Batch {
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
@Column(name="id")
private int id;
@Column(name="batch_number")
private int batchNumber;
@Column(name="batch_style")
private String batchStyle;
@Column(name="batch_name")
private String batchName;
@Column(name="batch_creation_date", columnDefinition="DATE")
@Temporal(TemporalType.TIMESTAMP)
private Date batchCreationDate;
@ManyToMany(fetch=FetchType.LAZY,
cascade= {CascadeType.PERSIST, CascadeType.MERGE,
CascadeType.DETACH, CascadeType.REFRESH})
@JoinTable(
name="batch_malt",
joinColumns=@JoinColumn(name="batch_id"),
inverseJoinColumns=@JoinColumn(name="malt_id")
)
private List<Malt> malts;
public Batch() {
}
public Batch(int batchNumber, String batchStyle, String batchName, Date batchCreationDate) {
this.batchNumber = batchNumber;
this.batchStyle = batchStyle;
this.batchName = batchName;
this.batchCreationDate = batchCreationDate;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public int getBatchNumber() {
return batchNumber;
}
public void setBatchNumber(int batchNumber) {
this.batchNumber = batchNumber;
}
public String getBatchStyle() {
return batchStyle;
}
public void setBatchStyle(String batchStyle) {
this.batchStyle = batchStyle;
}
public String getBatchName() {
return batchName;
}
public void setBatchName(String batchName) {
this.batchName = batchName;
}
public Date getBatchCreationDate() {
return batchCreationDate;
}
public void setBatchCreationDate(Date batchCreationDate) {
this.batchCreationDate = batchCreationDate;
}
public List<Malt> getMalts() {
return malts;
}
public void setMalts(List<Malt> malts) {
this.malts = malts;
}
@Override
public String toString() {
return "Batch [id=" + id + ", batchNumber=" + batchNumber + ", batchStyle=" + batchStyle + ", batchName="
+ batchName + ", batchCreationDate=" + batchCreationDate + ", malts=" + malts + "]";
}
// add a convenience method
public void addMalt(Malt theMalt) {
if (malts == null) {
malts = new ArrayList<>();
}
malts.add(theMalt);
}
}
Malt.class
package com.maruszka.entity;
import java.util.List;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.Table;
@Entity
@Table(name="malt")
public class Malt {
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
@Column(name="id")
private int id;
@Column(name="malt_name")
private String maltName;
@Column(name="malt_manufacturer")
private String maltManufacturer;
@Column(name="filling")
private int filling;
@Column(name="ebc")
private int ebc;
@Column(name="usage")
private String usage;
@ManyToMany(fetch=FetchType.LAZY,
cascade= {CascadeType.PERSIST, CascadeType.MERGE,
CascadeType.DETACH, CascadeType.REFRESH})
@JoinTable(
name="batch_malt",
joinColumns=@JoinColumn(name="malt_id"),
inverseJoinColumns=@JoinColumn(name="batch_id")
)
private List<Batch> batches;
public Malt() {
}
public Malt(String maltName, String maltManufacturer, int filling, int ebc, String usage) {
this.maltName = maltName;
this.maltManufacturer = maltManufacturer;
this.filling = filling;
this.ebc = ebc;
this.usage = usage;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getMaltName() {
return maltName;
}
public void setMaltName(String maltName) {
this.maltName = maltName;
}
public String getMaltManufacturer() {
return maltManufacturer;
}
public void setMaltManufacturer(String maltManufacturer) {
this.maltManufacturer = maltManufacturer;
}
public int getFilling() {
return filling;
}
public void setFilling(int filling) {
this.filling = filling;
}
public int getEbc() {
return ebc;
}
public void setEbc(int ebc) {
this.ebc = ebc;
}
public String getUsage() {
return usage;
}
public void setUsage(String usage) {
this.usage = usage;
}
public List<Batch> getBatches() {
return batches;
}
public void setBatches(List<Batch> batches) {
this.batches = batches;
}
@Override
public String toString() {
return "Malt [id=" + id + ", maltName=" + maltName + ", maltManufacturer=" + maltManufacturer + ", filling="
+ filling + ", ebc=" + ebc + ", usage=" + usage + ", batches=" + batches + "]";
}
}
CreateBatchAndMalt.class(main):
package com.maruszka.test;
import java.util.Date;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import com.maruszka.entity.Malt;
import com.maruszka.entity.Batch;
public class CreateBatchAndMalt {
public static void main(String[] args) {
// create session factory
SessionFactory factory = new Configuration()
.configure("hibernate.cfg.xml")
.addAnnotatedClass(Batch.class)
.addAnnotatedClass(Malt.class)
.buildSessionFactory();
// create session
Session session = factory.getCurrentSession();
try {
// start a transaction
session.beginTransaction();
// create a malt
Malt tempMalt = new Malt("Carafa (R) typ I", "Weyerman", 10, 900, "Stout, Porter, Schwarzbier");
// save the malt
System.out.println("\nSaving the malt ...");
session.save(tempMalt);
System.out.println("Saved the malt: " + tempMalt);
// create the batch
Date now = new Date();
Batch tempBatch = new Batch(2, "Mild", "Szatan", now);
// add malt to the batch
tempBatch.addMalt(tempMalt);
// save the batch
System.out.println("\nSaving batch ...");
session.save(tempBatch);
System.out.println("Saved batch: " + tempBatch.getMalts());
// commit transaction
session.getTransaction().commit();
System.out.println("Done!");
}
finally {
// close session
session.close();
factory.close();
}
}
}
的pom.xml:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.maruszka</groupId>
<artifactId>maruszka</artifactId>
<packaging>war</packaging>
<version>1.0</version>
<name>maruszka Maven Webapp</name>
<url>http://maven.apache.org</url>
<properties>
<springframework.version>5.0.2.RELEASE</springframework.version>
<springsecurity.version>5.0.1.RELEASE</springsecurity.version>
<hibernate.version>5.3.1.Final</hibernate.version>
<!-- 5.2.12.Final -->
<mysql.connector.version>5.1.38</mysql.connector.version>
<c3po.version>0.9.5.2</c3po.version>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
<dependencies>
<!-- Add support for JUnit -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<!-- Spring MVC support -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${springframework.version}</version>
</dependency>
<!-- Add support for Spring Tags -->
<dependency>
<groupId>org.springframework.security</groupId>
<artifactId>spring-security-taglibs</artifactId>
<version>${springsecurity.version}</version>
</dependency>
<!-- Hibernate Core -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>${hibernate.version}</version>
</dependency>
<!-- Hibernate Validator -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-validator</artifactId>
<version>6.0.4.Final</version>
</dependency>
<!-- Add MySQL and C3P0 support -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>${mysql.connector.version}</version>
</dependency>
<!-- dependency>
<groupId>com.mchange</groupId>
<artifactId>c3p0</artifactId>
<version>0.9.5.2</version>
</dependency-->
</dependencies>
<build>
<!-- TO DO: Add support for Maven WAR Plugin -->
<finalName>maruszka</finalName>
<pluginManagement>
<plugins>
<plugin>
<!-- Add Maven coordinates for: maven-war-plugin -->
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>3.2.0</version>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>
hibernate.cfg.xml(在maruszka \ src \ main \ resources \ hibernate.cfg.xml中):
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<!-- JDBC Database connection settings -->
<property name="connection.driver_class">com.mysql.cj.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://localhost:3306/maruszka?serverTimezone=UTC</property>
<!-- &useSSL=false -->
<property name="connection.username">***</property>
<property name="connection.password">***</property>
<!-- JDBC connection pool settings ... using built-in test pool -->
<property name="connection.pool_size">1</property>
<!-- Select our SQL dialect -->
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<!-- Echo the SQL to stdout -->
<property name="show_sql">false</property>
<!-- Set the current session context -->
<property name="current_session_context_class">thread</property>
</session-factory>
</hibernate-configuration>
数据库脚本:
CREATE DATABASE IF NOT EXISTS `maruszka`;
USE `maruszka`;
SET FOREIGN_KEY_CHECKS=0;
-- batch
DROP TABLE IF EXISTS `batch`;
CREATE TABLE `batch` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`batch_number` int(3) NOT NULL,
`batch_style` varchar(45) DEFAULT NULL,
`batch_name` varchar(45) DEFAULT NULL,
`batch_creation_date` DATE,
PRIMARY KEY (`id`),
UNIQUE KEY(`batch_number`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=latin1;
LOCK TABLE `batch` WRITE;
INSERT INTO `batch` VALUES
(1, 1, 'Stout', 'Happy Stout', '2018-06-06');
UNLOCK TABLES;
-- malt
DROP TABLE IF EXISTS `malt`;
CREATE TABLE `malt` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`malt_name` varchar(45) DEFAULT NULL,
`malt_manufacturer` varchar(45) DEFAULT NULL,
`filling` int(3) DEFAULT NULL,
`ebc` int(3) DEFAULT NULL,
`usage` varchar(254) DEFAULT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY(`malt_name`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=latin1;
LOCK TABLES `malt` WRITE;
INSERT INTO `malt` VALUES
(1, 'Pale Ale', 'Malteurop', 100, 6, 'All');
UNLOCK TABLES;
-- join table for batch - malt
DROP TABLE IF EXISTS `batch-malt`;
CREATE TABLE `batch-malt` (
`batch_id` int(11) NOT NULL,
`malt_id` int(11) NOT NULL,
PRIMARY KEY (`batch_id`, `malt_id`),
-- fk_[referencing table name]_[referenced table name]_[referencing field name]
CONSTRAINT `FK_BATCH_MALT_ID` FOREIGN KEY (`malt_id`)
REFERENCES `malt` (`id`)
ON DELETE NO ACTION ON UPDATE NO ACTION,
CONSTRAINT `FK_MALT_BATCH_ID` FOREIGN KEY (`batch_id`)
REFERENCES `batch` (`id`)
ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
SET FOREIGN_KEY_CHECKS=1;
在8.0.11版中使用mysql连接器时:
cze 06, 2018 9:33:53 PM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {5.3.1.Final}
cze 06, 2018 9:33:53 PM org.hibernate.cfg.Environment <clinit>
INFO: HHH000206: hibernate.properties not found
cze 06, 2018 9:33:53 PM org.hibernate.annotations.common.reflection.java.JavaReflectionManager <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {5.0.3.Final}
cze 06, 2018 9:33:53 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
WARN: HHH10001002: Using Hibernate built-in connection pool (not for production use!)
cze 06, 2018 9:33:53 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001005: using driver [com.mysql.cj.jdbc.Driver] at URL [jdbc:mysql://localhost:3306/maruszka?serverTimezone=UTC]
cze 06, 2018 9:33:53 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001001: Connection properties: {user=root, password=****}
cze 06, 2018 9:33:53 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001003: Autocommit mode: false
cze 06, 2018 9:33:53 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections <init>
INFO: HHH000115: Hibernate connection pool size: 1 (min=1)
Wed Jun 06 21:33:53 CEST 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
cze 06, 2018 9:33:53 PM org.hibernate.dialect.Dialect <init>
INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect
cze 06, 2018 9:33:54 PM org.hibernate.validator.internal.util.Version <clinit>
INFO: HV000001: Hibernate Validator 6.0.4.Final
Saving the malt ...
cze 06, 2018 9:33:54 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
WARN: SQL Error: 1064, SQLState: 42000
cze 06, 2018 9:33:54 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
ERROR: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'usage) values (900, 10, 'Weyerman', 'Carafa (R) typ I', 'Stout, Porter, Schwarzb' at line 1
cze 06, 2018 9:33:54 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl stop
INFO: HHH10001008: Cleaning up connection pool [jdbc:mysql://localhost:3306/maruszka?serverTimezone=UTC]
Exception in thread "main" org.hibernate.exception.SQLGrammarException: could not execute statement
at org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert(SQLExceptionTypeDelegate.java:63)
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:111)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:97)
at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:178)
at org.hibernate.dialect.identity.GetGeneratedKeysDelegate.executeAndExtract(GetGeneratedKeysDelegate.java:57)
at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:42)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3037)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3628)
at org.hibernate.action.internal.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:81)
at org.hibernate.engine.spi.ActionQueue.execute(ActionQueue.java:645)
at org.hibernate.engine.spi.ActionQueue.addResolvedEntityInsertAction(ActionQueue.java:282)
at org.hibernate.engine.spi.ActionQueue.addInsertAction(ActionQueue.java:263)
at org.hibernate.engine.spi.ActionQueue.addAction(ActionQueue.java:317)
at org.hibernate.event.internal.AbstractSaveEventListener.addInsertAction(AbstractSaveEventListener.java:359)
at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:292)
at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:200)
at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:131)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:192)
at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:38)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:177)
at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:32)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:73)
at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:709)
at org.hibernate.internal.SessionImpl.save(SessionImpl.java:701)
at org.hibernate.internal.SessionImpl.save(SessionImpl.java:696)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.hibernate.context.internal.ThreadLocalSessionContext$TransactionProtectionWrapper.invoke(ThreadLocalSessionContext.java:349)
at com.sun.proxy.$Proxy36.save(Unknown Source)
at com.maruszka.test.CreateBatchAndMalt.main(CreateBatchAndMalt.java:42)
Caused by: java.sql.SQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'usage) values (900, 10, 'Weyerman', 'Carafa (R) typ I', 'Stout, Porter, Schwarzb' at line 1
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:118)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:95)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:122)
at com.mysql.cj.jdbc.ClientPreparedStatement.executeInternal(ClientPreparedStatement.java:960)
at com.mysql.cj.jdbc.ClientPreparedStatement.executeUpdateInternal(ClientPreparedStatement.java:1116)
at com.mysql.cj.jdbc.ClientPreparedStatement.executeUpdateInternal(ClientPreparedStatement.java:1066)
at com.mysql.cj.jdbc.ClientPreparedStatement.executeLargeUpdate(ClientPreparedStatement.java:1396)
at com.mysql.cj.jdbc.ClientPreparedStatement.executeUpdate(ClientPreparedStatement.java:1051)
at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:175)
... 28 more
我已经仔细检查了语法,但无法弄清楚是什么造成这种情况:
ERROR: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'usage) values (900, 10, 'Weyerman', 'Carafa (R) typ I', 'Stout, Porter, Schwarzb' at line 1
祝你好运
答案 0 :(得分:4)
在您的sql表malt
中,您有一个名为usage
的列,该名称为reserved word in MySQL,这就是您的插入查询无效的原因。
最简单的方法是将名称更改为其他名称,例如malt_usage
所以这不起作用:
INSERT INTO malt(filling, ebc, malt_manufacturer, malt_name, usage)
VALUES (900, 10, 'Weyerman', 'Carafa (R) typ I', 'Stout, Porter, Schwarzb')
但这将
INSERT INTO malt(filling, ebc, malt_manufacturer, malt_name, malt_usage)
VALUES (900, 10, 'Weyerman', 'Carafa (R) typ I', 'Stout, Porter, Schwarzb')
在java中这不是问题,因此如果需要,可以保留名称usage
@Column(name="malt_usage")
private String usage;
答案 1 :(得分:2)
文字usage
是mysql中的关键字。
https://dev.mysql.com/doc/refman/8.0/en/keywords.html#keywords-8-0-detailed-U
最简单的解决方案是简单地将列名更改为另一个(非关键字)术语。
否则,请尝试设置
hibernate.auto_quote_keyword=true