JDBC的增删改查
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获取信息:
import java.sql.
/**
* 获取用户所有信息
*/
public class Insert {
public static void main(String[] args)throws Exception {
Insert a = new Insert();
a.student();
}
public void student()throws Exception{
Connection conn = null;
Statement stmt = null;
ResultSet rs = null ;
try {
//加载驱动类
Class.forName("com.mysql.jdbc.Driver");
//创建数据库连接
conn= DriverManager.getConnection("jdbc:mysql://localhost:3306/wuyi","root","010510");
//创建执行sql语句的对象
stmt = conn.createStatement();
//创建sql语句
String sql = "select * from student1";
//执行sql语句,得到rs指针
rs=stmt.executeQuery(sql);
while (rs.next()){
System.out.println(rs.getInt("studentNo")+" "+rs.getString("studentName"));
}
}catch (ClassCastException e){
e.printStackTrace();
}catch (SQLException e){
e.printStackTrace();
}finally {
try {
if (conn!=null){
conn.close();
}
if (stmt!=null){
stmt.close();
}
if (rs!=null){
rs.close();
}
}catch (SQLException e){
e.printStackTrace();
}
}
}
}
添加数据
import java.sql.*;
/**
* 新增
*/
public class Add {
public static void main(String[] args)throws Exception {
Add a = new Add();
a.add("123","你爸爸",2 );
}
public int add(String loginPwd , String studentName,int id)throws Exception{
Connection conn = null;
PreparedStatement stmt = null;
int count=0;
try {
//加载驱动类
Class.forName("com.mysql.jdbc.Driver");
//创建数据库连接
conn= DriverManager.getConnection("jdbc:mysql://localhost:3306/wuyi","root","010510");
//创建sql语句
String sql = "insert into student2(loginPwd,studentName,id) values(?,?,?)";
//创建sql语句的对象
stmt= conn.prepareStatement(sql);
stmt.setString(1,loginPwd);
stmt.setString(2,studentName);
stmt.setInt(3,id);
//执行sql语句
count=stmt.executeUpdate();
}catch (ClassNotFoundException e){
e.printStackTrace();
}catch (SQLException e){
e.printStackTrace();
}finally {
try {
if (conn!=null){
conn.close();
}
if (stmt!=null){
stmt.close();
}
}catch (SQLException e){
e.printStackTrace();
}
}
return count;
}
}
改数据
import *
/**
* 改数据
*/
public class Update {
public static void main(String[] args)throws Exception {
Update a = new Update();
a.show(10000,"憨憨");
}
public int show(int studentNo ,String studentName )throws Exception{
Connection conn=null;
PreparedStatement stmt = null ;
int count= 0;
try {
//加载驱动类
Class.forName("com.mysql.jdbc.Driver");
//创建数据库连接
conn= DriverManager.getConnection("jdbc:mysql://localhost:3306/wuyi","root","010510");
//创建sql语句
stmt=conn.prepareStatement("update student1 set studentName=? where studentNo=?");
stmt.setString(1,studentName);
stmt.setInt(2,studentNo);
//执行sql语句
count=stmt.executeUpdate();
}catch (ClassNotFoundException e){
e.printStackTrace();
}catch (SQLException e){
e.printStackTrace();
}finally {
if(conn!=null){
conn.close();
}
if (stmt!=null){
stmt.close();
}
}
return count;
}
}
删除数据
import *
/**
* 删除信息
*/
public class Delete {
public static void main(String[] args)throws Exception {
Delete a = new Delete();
a.delete(2);
}
public int delete(int id)throws Exception{
Connection conn= null;
PreparedStatement stmt = null;
int count =0;
try {
//加载驱动类
Class.forName("com.mysql.jdbc.Driver");
//创建数据库连接
conn= DriverManager.getConnection("jdbc:mysql://localhost:3306/wuyi","root","010510");
//关闭自动提交
conn.setAutoCommit(false);
//创建sql语句的对象
stmt=conn.prepareStatement("delete from student2 where id=?");
stmt.setInt(1,id);
//执行sql语句
count=stmt.executeUpdate();
//编程式事务
//手动提交事务
conn.commit();
}catch (ClassNotFoundException e){
e.printStackTrace();
}catch (SQLException e){
e.printStackTrace();
//手动滚回
if (conn!=null){
conn.rollback();
}
}finally {
try {
if (conn!=null);{
conn.close();
}
if (stmt!=null){
stmt.close();
}
}catch (SQLException e){
e.printStackTrace();
}
}
return count;
}
}
查询数据
import java.sql.*;
/**
* 根据ID查询学生
*/
public class Select {
public static void main(String[]args) throws Exception{
Select a = new Select();
a.Select1(10000);
}
public void Select1(int id)throws Exception{
Connection conn=null;
Statement stmt=null;
ResultSet rs=null;
try{
//加载驱动器
Class.forName("com.mysql.jdbc.Driver");
//创建数据库连接
conn= DriverManager.getConnection("jdbc:mysql://localhost:3306/wuyi","root","010510");
//创建sql语句的对象
stmt=conn.createStatement();
//创建一条sql语句
String sql="select * from student1 where studentNo="+id;
//执行sql语句,得到rs指针
rs=stmt.executeQuery(sql);
//通过rs获得单元格
while(rs.next()){
System.out.println(rs.getInt("studentNo")+" "+rs.getString("studentName"));
}
}catch(ClassCastException e){
e.printStackTrace();
}catch(SQLException e){
e.printStackTrace();
}finally{
try{
if(conn!=null){
conn.close();
}
if(stmt!=null){
stmt.close();
}
if(rs!=null){
rs.close();
}
}catch(SQLException e){
e.printStackTrace();
}
}
}
}
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