Java中对数据的基本操作,删除、插入、更新、查询。
发布网友
发布时间：2022-04-23 01:55
共4个回答
热心网友
时间：2022-04-08 08:55
* 将pojo数据保存到数据库
* @throws DataAccessException
*/
public void save(Object object) throws DataAccessException {
getHibernateTemplate().save(object);
}
/*
* (non-Javadoc)
*
* @see com.stockmanage..IDao#update(java.lang.Object)
*/
/**
* 将pojo数据更新到数据库
* @throws DataAccessException
*/
public void update(Object object) throws DataAccessException {
getHibernateTemplate().update(object);
}
/**
* 保存或更新pojo数据到数据库
* @throws DataAccessException
*/
public void saveorupdate(Object object)throws DataAccessException{
getHibernateTemplate().saveOrUpdate(object);
}
/*
* (non-Javadoc)
*
* @see com.stockmanage..IDao#delete(java.lang.Object)
*/
/**
* 根据pojo数据删除数据库中的数据
* @throws DataAccessException
*/
public void delete(Object object) throws DataAccessException {
getHibernateTemplate().delete(object);
}
/*
* (non-Javadoc)
*
* @see com.stockmanage..IDao#findById(java.lang.Class,
* java.io.Serializable)
*/
/**
* 根据id查找数据
* @throws DataAccessException
* @return 返回根据id查询到的pojo对象
*/
@SuppressWarnings("unchecked")
public Object findById(Class clazz, Serializable id)
throws DataAccessException {
Object object = getHibernateTemplate().get(clazz, id);
return object;
}
/*
* (non-Javadoc)
*
* @see com.stockmanage..IDao#findByHql(java.lang.String)
*/
/**
* 根据hql语句查询数据
* @throws DataAccessException
* @return 返回根据hql语句查询到的pojo对象
*/
@SuppressWarnings("unchecked")
public List findByHql(String hql) throws DataAccessException {
List<Object> list = getHibernateTemplate().find(hql);
return list;
}
/*
* (non-Javadoc)
*
* @see com.stockmanage..IDao#findByCriteria(org.hibernate.criterion.DetachedCriteria)
*/
/**
* 根据criteria条件查询数据
* @throws DataAccessException
* @return 返回根据criteria条件查询到的pojo对象
*/
@SuppressWarnings("unchecked")
public List findByCriteria(DetachedCriteria criteria)
throws DataAccessException {
List<Object> list = getHibernateTemplate().findByCriteria(criteria);
return list;
}
/*
* (non-Javadoc)
*
* @see com.stockmanage..IDao#findByExample(java.lang.Object)
*/
/**
* 根据pojo对象查询数据
* @throws DataAccessException
* @return 返回根据pojo对象查询到的pojo对象
*/
@SuppressWarnings("unchecked")
public List findByExample(Object object) throws DataAccessException {
List list = getHibernateTemplate().findByExample(object);
return list;
}
/**
* 根据sql语句查询封装为对象的数据集合
* @throws DataAccessException
* @return 返回根据sql语句查询到的数据集合
*/
@SuppressWarnings("unchecked")
public List findBySql(final String sql,final Class... entity) throws DataAccessException{
return (List) getHibernateTemplate().execute(new HibernateCallback(){
public List doInHibernate(Session session)
throws HibernateException, SQLException {
SQLQuery query = session.createSQLQuery(sql);
for (Class clazz : entity) {
query = query.addEntity(clazz);
}
List list = query.list();
return list;
}
});
}
/**
* 根据sql语句查询数据
* @throws DataAccessException
* @return 返回根据sql语句查询到的数据集合
*/
@SuppressWarnings("unchecked")
public List findBySql(final String sql) throws DataAccessException{
return (List) getHibernateTemplate().execute(new HibernateCallback(){
public List doInHibernate(Session session)
throws HibernateException, SQLException {
List list = session.createSQLQuery(sql).list();
return list;
}
});
}
以上是hibernet的数据库操作基类。有疑问请追问。
热心网友
时间：2022-04-08 10:13
热心网友
时间：2022-04-08 11:48
工具类
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import cn.bjsxt.unicom.common.ConnectPoolFactory;
public abstract class BaseDao {
/**
* 获取jdbc连接
* @return
*/
public Connection getConnection1(){
//long start = System.currentTimeMillis();
String driverClassName="oracle.jdbc.OracleDriver";
String url = "jdbc:oracle:thin:@127.0.0.1:1521:orcl";
String user ="scott";
String password ="orcl";
Connection conn = null;
try {
Class.forName(driverClassName);
conn = DriverManager.getConnection(url, user, password);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
return conn;
}
/**
*执行修改数据库表的语句
* @return
*/
public Integer executeUpdate(String sql,Object...obj) {
Connection conn = null;
PreparedStatement pstmt = null;
Integer n =0;
try {
conn = this.getConnection1();
pstmt = conn.prepareStatement(sql);
for(int i=0;i<obj.length;i++){
pstmt.setObject(i+1, obj[i]);
}
n= pstmt.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
}finally{
this.closeAll(null, pstmt, conn);
}
return n;
}
public void closeAll(ResultSet rs,Statement stmt,Connection conn){
try {
if(rs!=null){
rs.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
try {
if(stmt != null){
stmt.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
try {
if(conn != null){
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
查询
List<Users> userlist = new ArrayList<Users>();
//获取链接
Connection conn = this.getConnection();
//sql语句，创建发送sql的stat
//String sql="SELECT * FROM USERS LEFT JOIN DEPT ON USERDEPT=DEPTNUM";//不分页sql
String sql="SELECT * FROM(SELECT A.*, ROWNUM RN FROM (SELECT * FROM USERS LEFT JOIN DEPT ON USERDEPT=DEPTNUM) A WHERE ROWNUM <="+pager.getEndRow()+")WHERE RN >="+pager.getStartRow();//分页sql 1-3条
//执行查询语句，并返回resultSet
try {
PreparedStatement stat = conn.prepareStatement(sql);
ResultSet rs = stat.executeQuery();
while(rs.next()){
Users users= new Users(rs.getInt("USERID"), rs.getString("USERNAME"), rs.getString("USERLOGINNAME"), rs.getString("USERPWD"), rs.getDate("ENTERDATE"), null, null,rs.getString("DEPTNAME"));
userlist.add(users);
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return userlist;
}
增加、修改、删除 全部调用this.executeUpdate(参数）
String sql="INSERT INTO USERS VALUES(?,?,?,?,?,?,?)";
this.executeUpdate(sql, users.getUserId(),users.getUserName(),
users.getUserLoginName(),users.getUserPwd(),new java.sql.Date
(users.getEnterDate().getTime()),users.getUserDept(),users.getUserRole());
}
热心网友
时间：2022-04-08 13:39
看下马士兵的教程,百度第一个就是,谢谢采纳，受人以鱼，不如受人以渔
