使用一个抽象的java类test,test中只有二个属性cname和dname。设置set/get方法
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2、提供默认构造函数和一个有参数的构造函数,这个有参数的构造函数的参数分别为cid,cname,cpwd,did,dname,dpwd
3、String sql="select new Test(cid,cname,cpwd,did,dname,dpwd
) from Test1 c,Test2 d where c.Cid=d.Did";执行返回List<Test>
你可以直接写sql
hibernate支持sql语句的是在不行 你可以几个表关联建立个视图,这个视图和你po进行映射,然后直接写hql就可以了
您好,我用您的hql语句试了试,出错了,信息为:
Unable to locate class [Test] [select new Test(CId,CName,DId,DName) from y.model.Test1 c,y.model.Test2 d where c.CId=d.DId]我的方法是:
public List<Test> getAll()
{
String sql="select new Test(CId,CName,DId,DName) from Test1 c,Test2 d where c.CId=d.DId";
return (List<Test>)super.find(sql);
}
另外我试了试用String sql="select new y.model.Test(CId,CName,DId,DName) from Test1 c,Test2 d where c.CId=d.DId";语句写,报的是空指针错误,请高手帮我解决一下吧,麻烦你了.另附上,test,test1,test2,映射类:
Test:
package y.model;import java.io.Serializable;
import java.util.Date;
/**
* 多表联合查询测试实体类
* @param classname
* @param info
* @param project
* @param classChineseName
*/public class Test implements Serializable {
//无参数构造方法
public Test()
{
super();
} //编号
private String CId;
public String getCId(){
return this.CId;
} public void setCId(String CId){
this.CId=CId;
}
//姓名
private String CName;
public String getCName(){
return this.CName;
} public void setCName(String CName){
this.CName=CName;
}
//编号
private String DId;
public String getDId(){
return this.DId;
} public void setDId(String DId){
this.DId=DId;
}
//姓名
private String DName;
public String getDName(){
return this.DName;
} public void setDName(String DName){
this.DName=DName;
}
//含参数构造方法
public Test(String cId,String cName,String dId,String dName)
{
super();
this.CId=cId;
this.CName=cName;
this.DId=dId;
this.DName=dName;
}
}Test1:
package y.model;import java.io.Serializable;
import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;
import org.hibernate.annotations.GenericGenerator;@Entity
@Table(name = "test1")
public class Test1 implements Serializable {
@Id
@GenericGenerator(name = "generator", strategy = "uuid.hex")
@GeneratedValue(generator = "generator") @Column(name = "C_Id")
private String CId; @Column(name = "C_Name")
private String CName; @Column(name = "C_Pwd")
private String CPwd; @Column(name = "C_Sex")
private String CSex; @Column(name = "C_Ago")
private String CAgo; public String getCId(){
return this.CId;
} public void setCId(String CId){
this.CId=CId;
} public String getCName(){
return this.CName;
} public void setCName(String CName){
this.CName=CName;
} public String getCPwd(){
return this.CPwd;
} public void setCPwd(String CPwd){
this.CPwd=CPwd;
} public String getCSex(){
return this.CSex;
} public void setCSex(String CSex){
this.CSex=CSex;
} public String getCAgo(){
return this.CAgo;
} public void setCAgo(String CAgo){
this.CAgo=CAgo;
}}Test2:package y.model;import java.io.Serializable;
import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;
import org.hibernate.annotations.GenericGenerator;@Entity
@Table(name = "test2")
public class Test2 implements Serializable {
@Id
@GenericGenerator(name = "generator", strategy = "uuid.hex")
@GeneratedValue(generator = "generator") @Column(name = "D_Id")
private String DId; @Column(name = "D_Name")
private String DName; @Column(name = "D_Pwd")
private String DPwd; @Column(name = "D_Age")
private Integer DAge; @Column(name = "D_Addr")
private String DAddr; @Column(name = "D_Sex")
private String DSex; public String getDId(){
return this.DId;
} public void setDId(String DId){
this.DId=DId;
} public String getDName(){
return this.DName;
} public void setDName(String DName){
this.DName=DName;
} public String getDPwd(){
return this.DPwd;
} public void setDPwd(String DPwd){
this.DPwd=DPwd;
} public Integer getDAge(){
return this.DAge;
} public void setDAge(Integer DAge){
this.DAge=DAge;
} public String getDAddr(){
return this.DAddr;
} public void setDAddr(String DAddr){
this.DAddr=DAddr;
} public String getDSex(){
return this.DSex;
} public void setDSex(String DSex){
this.DSex=DSex;
}}
import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.List;
import java.util.Vector;import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.Transaction;import y.model.Test;
import y.model.Test1;
import y.model.Test2;import com.targ.track.financeManager.buildProjectAccount.domain.BuildProjectAccount;
import com.targ.track.financeManager.buildProjectAccount.domain.BuildProjectAccountDetail;
import com.targ.track.startAppManager.domain.StartApplication;public class MyJunitTest {
@org.junit.Test
public void testDDL(){
//插入数据
HibernateTest.doInHibernateSession(new InHibernateSession(){
@Override
public Object doInHibernateSession(Session session) {
Test1 test1 = new Test1();
test1.setCAgo("CAgo");
test1.setCName("CName");
test1.setCPwd("CPwd");
test1.setCSex("CSex");
Test2 test2 = new Test2();
test2.setDAddr("DAddr");
test2.setDAge(123);
test2.setDName("DName");
test2.setDPwd("DPwd");
test2.setDSex("DSex");
session.save(test1);
session.save(test2);
return null;
}
});
//查询
List<Test> all = (List<Test>) HibernateTest.doInHibernateSession(new InHibernateSession(){
public Object doInHibernateSession(Session session) {
String sql="select new y.model.Test(c.CId,c.CName,d.DId,d.DName) from Test1 c,Test2 d where c.CId=d.DId";
Query query = session.createQuery(sql);
return query.list();
}
});
for(Test test : all){
System.out.println(test);
}
}
public static class HibernateTest {
public static Object doInHibernateSession(InHibernateSession doInHibernateSession){
Session session = HibernateSessionFactory.getSession();
Transaction transaction = session.beginTransaction();
try{
Object object = doInHibernateSession.doInHibernateSession(session);
transaction.commit();
return object;
}catch(RuntimeException e){
try{
System.err.println("rollback");
transaction.rollback();
}catch(RuntimeException ex){
System.err.println("回滚失败!");
}
throw e;
}finally{
//HibernateSessionFactory.closeSession();
} } }
public interface InHibernateSession {
public Object doInHibernateSession(Session session);
}}
String sql="select new Test(CId,CName,DId,DName) from Test1 c,Test2 d where c.CId=d.DId"要加前缀啊! c.CId c.CName d.DId d.DName
select b1.cid,b2.cid from table1 b1,table2 b2 where ....
①你想用聚合函数那没有问题啊
hql写成 select sum(c.CSCcoe) from Test1 c,Test2 d where c.CId=d.DId,其他你看着办。这问题你为什么不看官方文档啊?
②12楼的问题,用13楼回答。