JAVA数据库增删改查

package JDBC;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.Scanner;
public class Student {
/**
*
* 增加
*/
public void jdbc_add(){
try {
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
String url = "jdbc:sqlserver://localhost:1433;DatabaseName=Student";
Connection conn=DriverManager.getConnection(url,"sa","123");
String sq1 = "insert into Information(Studentnumber, Studentname, Studentclass, Studentsex, Studentadd) values(?,?,?,?,?);";
PreparedStatement ps = conn.prepareStatement(sq1);
ps.setObject(1, "1010");
ps.setObject(2, "大禹");
ps.setObject(3, "10");
ps.setObject(4, "男");
ps.setObject(5, "上海");
int r=ps.executeUpdate();
ps.close();
conn.close();
if(r>0){
System.out.println("插入成功!");
}else System.out.println("插入失败！");
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 删除
*
*/
public void jdbc_del(){
try {
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
String url="jdbc:sqlserver://localhost:1433;databasename=Student";
Connection conn=DriverManager.getConnection(url,"sa","123");
Statement st=conn.createStatement();
String sql="delete from Information where Studentname='杨伟';";
int flag=st.executeUpdate(sql);
if(flag>0){
System.out.println("删除成功！");
}else System.out.println("删除失败！");
} catch (Exception e) {
e.printStackTrace();
}
}
/*
* 修改
*/
public void jdbc_cha(){
try {
//1加载驱动类
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
//2.定义字符串
String url="jdbc:sqlserver://localhost:1433;databasename=Student";
//3.建立连接
Connection conn=DriverManager.getConnection(url,"sa","123");
//4.定义SQL语句修改
String sql="update Information set Studentname=? where Studentnumber=?";
PreparedStatement ps=conn.prepareStatement(sql);
ps.setObject(1, "杨伟");
ps.setObject(2, "1002");
int flag=ps.executeUpdate();
if(flag>0){
System.out.println("修改成功！");
}else System.out.println("修改失败！");
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 查询
* @param args
*/
public void jdbc_find(){
try {
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
String url="jdbc:sqlserver://localhost:1433;databasename=Student";
Connection conn=DriverManager.getConnection(url,"sa","123");
Scanner input=new Scanner(System.in);
System.out.print("请输入姓名：");
String studentname = input.next();
String sql="select *from Information where Studentname=?;";
PreparedStatement ps=conn.prepareStatement(sql);
ps.setObject(1, studentname);
ResultSet rs=ps.executeQuery();
while (rs.next()) {
System.out.println("您查询的信息为："+rs.getObject("studentname"));
}
int flag=ps.executeUpdate();
rs.close();
ps.close();
conn.close();
if(flag>0){
}else System.out.println("查询失败！您要查询的信息不存在！");
input.close();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
Student test=new Student();
test.jdbc_add();
test.jdbc_del();
test.jdbc_cha();
test.jdbc_find();
}
}。