MySQL 表被覆盖怎么恢复

1 找个别的机器安装个同版本的mysql或从已安装同版本的其他机器上（非同版本的也可以试下）： 拷贝 mysql/data/mysql 目录到你的mysql/data/ 下吧 2 试着启动mysql服务，如果能启动了，理论上应该丢失的只有用户、授权等一些系统信息

ResultSet 只有当前数据库连接存在时才有效，迭代循环是每次只能获取当前游标下数据：

所以你需要建立其他容器将获取的数据存储下来，我刚刚写的这个文件，是相当普通的一个DAO文件结构模式，可以好好看下。会让以后的工作变得更加得心应手。呵呵。

唉！我大餐都给你做好了，你还叫我往嘴里喂啊！

List<String>poList = new LinkedList<String>()

List<String>pnList = new LinkedList<String>()

List<String>prList = new LinkedList<String>()

while(res.next()){

po=res.getString("pno")poList.add(po)

pn=res.getString("pname")pnList.add(pn)

pr=res.getString("price")prList.add(pr)

}

/**************************************************************************************************/

import java.sql.*

import java.util.LinkedList

import java.util.List

/**课题：封装数据库的增删改查的工具类的实现。

*

* 假设相关数据库的表结构如下：

* 表名：user

* 列名及属性：id(int 自增)，name(varchar(20))，tele(char(12))，birthday(date)

* @author shy2850

*/

public class UserDAO {

Connection conn

public UserDAO(Connection conn) {

this.conn = conn

}

public int save(User user) throws SQLException {

String sql = "insert into user values(0,?,?,?)"

PreparedStatement pstmt = conn.prepareStatement(sql)

pstmt.setString(1, user.getName())

pstmt.setString(2, user.getTele())

pstmt.setDate(3, user.getBirthday())

int n = pstmt.executeUpdate()

pstmt.close()

return n

}

public int delete(User user) throws SQLException{

String sql = "delete from user where id = "+user.getId()

Statement stmt = conn.createStatement()

int n = stmt.executeUpdate(sql)

stmt.close()

return n

}

public int update(User user) throws SQLException{

String sql = "update user set name=?, tele=?, birthday=? where id = "+user.getId()

PreparedStatement pstmt = conn.prepareStatement(sql)

pstmt.setString(2, user.getName())

pstmt.setString(3, user.getTele())

pstmt.setDate(4, user.getBirthday())

int n = pstmt.executeUpdate(sql)

pstmt.close()

return n

}

public User getUser(Integer id) throws SQLException{

String sql = "select * from user where id = " + id

Statement stmt = conn.createStatement()

ResultSet rs = stmt.executeQuery(sql)

User user = getUserFromResultSet(rs)

rs.close()

stmt.close()

return user

}

public List<User>getAll() throws SQLException{

List<User>userList = new LinkedList<User>()

String sql = "select * from user "

Statement stmt = conn.createStatement()

ResultSet rs = stmt.executeQuery(sql)

while (rs.next()) {

User u = getUserFromResultSet(rs)

userList.add(u)

}

return userList

}

static User getUserFromResultSet(ResultSet rs) throws SQLException{

Integer id = rs.getInt("id")

String name= rs.getString("name")

String tele= rs.getString("tele")

Date birthday = rs.getDate("birthday")

return new User(id, name, tele, birthday)

}

}

/**

* 构建数据库表的java类映射

*/

class User{

private Integer id

private String name

private String tele

private Date birthday

public User() {

}

public User(Integer id, String name, String tele, Date birthday) {

super()

this.id = id

this.name = name

this.tele = tele

this.birthday = birthday

}

public Integer getId() {

return id

}

public void setId(Integer id) {

this.id = id

}

public String getName() {

return name

}

public void setName(String name) {

this.name = name

}

public String getTele() {

return tele

}

public void setTele(String tele) {

this.tele = tele

}

public Date getBirthday() {

return birthday

}

public void setBirthday(Date birthday) {

this.birthday = birthday

}

}

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