今天在MySQL中用hibernate测试update语句发现以下问题：
update语句竟然不去作用；
表机构如下：
create table student
(sid int primary key ,
sname varchar(45) not null,
ssex char(2) not null,
sdept varchar(10) not null,
sage int ,
saddress varchar(45)
);
update语句如下：
String[] params = new String[] { "20", "成龙" };
HibernateUtil.executeUpdate(
"update Student s set s.sage=? where s.sname=?",params);
package com.huml.util; import java.util.ArrayList;
import java.util.Arrays; import org.hibernate.Transaction; import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration; public class HibernateUtil {
private static final SessionFactory sf;
private static ThreadLocal<Session> threadLocal = new ThreadLocal<Session>();
static {
sf = new Configuration().configure().buildSessionFactory();
} private HibernateUtil() { } public static Session openSession() {
return sf.openSession();
} public static Session getcurrentSession() {
Session session = threadLocal.get(); if (session == null) {
session = sf.openSession();
threadLocal.set(session);
}
return session;
} public static void save(Object obj) {
Session session = openSession();
Transaction tx = null; try {
tx = session.beginTransaction();
session.save(obj);
tx.commit();
} catch (Exception e) {
if (tx != null) {
tx.rollback();
}
throw new RuntimeException(e.getMessage());
} finally {
if (session != null && session.isOpen()) {
session.close();
}
}
} @SuppressWarnings("unchecked")
public static ArrayList executeQuery(String hql, String... params) {
Session session = openSession();
Transaction tx = null;
ArrayList list = null;
try {
tx = session.beginTransaction();
Query query = session.createQuery(hql); if (params != null && params.length > 0) {
for (int i = 0; i < params.length; i++) {
query.setParameter(i, params[i]);
}
}
list = (ArrayList) query.list();
tx.commit();
} catch (Exception e) {
if (tx != null)
tx.rollback();
throw new RuntimeException(e.getMessage());
} finally {
if (session != null && session.isOpen()) {
session.close();
}
}
return list;
} public static void executeUpdate(String hql, String... params) { Session session = openSession();
Transaction tx = null; try {
tx = session.beginTransaction();
Query query = session.createQuery(hql); if (params != null && params.length > 0) {
for (int i = 0; i < params.length; i++) {
query.setParameter(i, params[i]);
// System.out.println("query influenced: "+params[i]);
}
}
System.out.println("query influenced: " + query.getQueryString());
int n = query.executeUpdate();
System.out.println("query influence: " + n);
tx.commit();
} catch (Exception e) {
if (tx != null)
tx.rollback();
throw new RuntimeException(e.getMessage());
} finally {
if (session != null && session.isOpen()) {
session.close();
}
}
} }
原因是MySQL中不能自动把String类型转换成Integer，在Oracle中可以修改代码如下：
Object[] params = new Object[] { 20, "成龙" };
HibernateUtil.executeUpdate(
"update Student s set s.sage=? where s.sname=?",params);
package com.huml.util; import java.util.ArrayList;
import java.util.Arrays; import org.hibernate.Transaction; import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration; public class HibernateUtil {
private static final SessionFactory sf;
private static ThreadLocal<Session> threadLocal = new ThreadLocal<Session>();
static {
sf = new Configuration().configure().buildSessionFactory();
} private HibernateUtil() { } public static Session openSession() {
return sf.openSession();
} public static Session getcurrentSession() {
Session session = threadLocal.get(); if (session == null) {
session = sf.openSession();
threadLocal.set(session);
}
return session;
} public static void save(Object obj) {
Session session = openSession();
Transaction tx = null; try {
tx = session.beginTransaction();
session.save(obj);
tx.commit();
} catch (Exception e) {
if (tx != null) {
tx.rollback();
}
throw new RuntimeException(e.getMessage());
} finally {
if (session != null && session.isOpen()) {
session.close();
}
}
} @SuppressWarnings("unchecked")
public static ArrayList executeQuery(String hql, String... params) {
Session session = openSession();
Transaction tx = null;
ArrayList list = null;
try {
tx = session.beginTransaction();
Query query = session.createQuery(hql); if (params != null && params.length > 0) {
for (int i = 0; i < params.length; i++) {
query.setParameter(i, params[i]);
}
}
list = (ArrayList) query.list();
tx.commit();
} catch (Exception e) {
if (tx != null)
tx.rollback();
throw new RuntimeException(e.getMessage());
} finally {
if (session != null && session.isOpen()) {
session.close();
}
}
return list;
} public static void executeUpdate(String hql, Object... params) { Session session = openSession();
Transaction tx = null; try {
tx = session.beginTransaction();
Query query = session.createQuery(hql); if (params != null && params.length > 0) {
for (int i = 0; i < params.length; i++) {
query.setParameter(i, params[i]);
// System.out.println("query influenced: "+params[i]);
}
}
System.out.println("query influenced: " + query.getQueryString());
int n = query.executeUpdate();
System.out.println("query influence: " + n);
tx.commit();
} catch (Exception e) {
if (tx != null)
tx.rollback();
throw new RuntimeException(e.getMessage());
} finally {
if (session != null && session.isOpen()) {
session.close();
}
}
}
}
这样就成功了；