Question

我有3张桌子

城市，学院和大学。

城市有许多与大学的映射

大学与学院有多对一的映射。

但是当我插入数据时，我得到了异常。

Caused by: org.postgresql.util.PSQLException: ERROR: syntax error at or near   "table"
 Position: 13
 at   org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2198)
at   org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1927)
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:255)
at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:561)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:419)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeUpdate(AbstractJdbc2Statement.java:365)
at   org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:186)
... 21 more



@Entity
@Table(name="city")
public class City {

@Id
@GeneratedValue(strategy= GenerationType.IDENTITY)
private long cityID;
private String cityName;
@ManyToOne
@JoinColumn(name="state_id")
private State state;
@ManyToMany(cascade = CascadeType.ALL)
@JoinTable(
        name = "city_university",
        joinColumns = @JoinColumn(name = "cityID"),
        inverseJoinColumns = @JoinColumn(name = "universityID")
)
private Set<University> universities = new HashSet<University>();


/**
 * @return the cityID
 */
public long getCityID() {
    return cityID;
}
/**
 * @param cityID the cityID to set
 */
public void setCityID(long cityID) {
    this.cityID = cityID;
}
/**
 * @return the cityName
 */
public String getCityName() {
    return cityName;
}
/**
 * @param cityName the cityName to set
 */
public void setCityName(String cityName) {
    this.cityName = cityName;
}
/**
 * @return the state
 */
public State getState() {
    return state;
}
/**
 * @param state the state to set
 */
public void setState(State state) {
    this.state = state;
}
/**
 * @return the universities
 */
public Set<University> getUniversities() {
    return universities;
}
/**
 * @param universities the universities to set
 */
public void setUniversities(Set<University> universities) {
    this.universities = universities;
}




}


/**

* * / 包com.junaid.model;

import java.util.HashSet;
import java.util.Set;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.ManyToMany;
import javax.persistence.OneToMany;
import javax.persistence.Table;

/**
* @author jamju02
*
*/
@Entity
@Table(name="university")
public class University {

@Id
@GeneratedValue(strategy= GenerationType.IDENTITY)
private long universityID;
private String universityName;
@ManyToMany(mappedBy = "universities")
private Set<City> cities = new HashSet<City>();
@OneToMany(mappedBy="university")
private Set<College> colleges;


/**
 * @return the universityID
 */
public long getUniversityID() {
    return universityID;
}
/**
 * @param universityID the universityID to set
 */
public void setUniversityID(long universityID) {
    this.universityID = universityID;
}
/**
 * @return the universityName
 */
public String getUniversityName() {
    return universityName;
}
/**
 * @param universityName the universityName to set
 */
public void setUniversityName(String universityName) {
    this.universityName = universityName;
}
/**
 * @return the cities
 */
public Set<City> getCities() {
    return cities;
}
/**
 * @param cities the cities to set
 */
public void setCities(Set<City> cities) {
    this.cities = cities;
}
/**
 * @return the colleges
 */
public Set<College> getColleges() {
    return colleges;
}
/**
 * @param colleges the colleges to set
 */
public void setColleges(Set<College> colleges) {
    this.colleges = colleges;
}


}


/**
* 
*/
package com.junaid.model;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Table;

/**
 * @author jamju02
 *
 */
@Entity
@Table(name="table")
public class College {

@Id
@GeneratedValue(strategy= GenerationType.IDENTITY)
private long collegeID;
private String collegeName;
@ManyToOne
@JoinColumn(name="university_id")
private University university;

/**
 * @return the collegeID
 */
public long getCollegeID() {
    return collegeID;
}
/**
 * @param collegeID the collegeID to set
 */
public void setCollegeID(long collegeID) {
    this.collegeID = collegeID;
}
/**
 * @return the collegeName
 */
public String getCollegeName() {
    return collegeName;
}
/**
 * @param collegeName the collegeName to set
 */
public void setCollegeName(String collegeName) {
    this.collegeName = collegeName;
}

/**
 * @return the university
 */
public University getUniversity() {
    return university;
}
/**
 * @param university the university to set
 */
public void setUniversity(University university) {
    this.university = university;
}




}

插入数据的主要类是

public class Test{

/*  public void testApp() {
    SessionFactory sessionFactory = new Configuration().configure()
            .buildSessionFactory();
    Session session = sessionFactory.openSession();
    session.beginTransaction();

    Country cou = new Country();
    cou.setCountryName("India");
    session.save(cou);

    State state1 = new State();
    State state2 = new State();
    state1.setStateName("Karnataka");
    state1.setCountry(cou);
    state2.setStateName("Tamil Nadu");
    state2.setCountry(cou);
    session.save(state1);
    session.save(state2);

    session.getTransaction().commit();
    session.close();
}*/

public static void main(String[] arg){
    SessionFactory sessionFactory = new Configuration().configure()
            .buildSessionFactory();
    Session session = sessionFactory.openSession();
    session.beginTransaction();
    Country cou = new Country();
    cou.setCountryName("India");
    session.save(cou);

    State state1 = new State();
    State state2 = new State();
    state1.setStateName("Karnataka");
    state1.setCountry(cou);
    state2.setStateName("Tamil Nadu");
    state2.setCountry(cou);
    session.save(state1);
    session.save(state2);

    City c1 = new City();
    c1.setCityName("Bangalore");
    c1.setState(state1);

    City c2 = new City();
    c2.setCityName("Chennai");
    c2.setState(state2);




    University university1 = new University();
    university1.setUniversityName("VTU");
    university1.getCities().add(c1);
    University university2 = new University();
    university2.setUniversityName("ANNA");
    university2.getCities().add(c2);

    c1.getUniversities().add(university1);
    c2.getUniversities().add(university2);







    session.save(c1);
    session.save(c2);

    session.getTransaction().commit();
    session.close();


/*  SessionFactory sessionFactory1 = new Configuration().configure()
            .buildSessionFactory();
    Session session1 = sessionFactory1.openSession();
    session1.beginTransaction();
    College col1 = new College();
    col1.setCollegeName("HKBK");
    col1.setUniversity(university1);

    College col2 = new College();
    col2.setCollegeName("test");
    col2.setUniversity(university2);
    session1.save(col1);
    session1.getTransaction().commit();
    session1.close();*/

}
}

Answer 1

@Table(name="table")

为College表选择另一个名称。 college将是一个更好的选择。 table是一个SQL关键字。

在休眠中插入记录

1 个答案: