第六章 JDBC

1，在MySQL创建一个student表，添加数据，然后在控制台输出目前表中记录的总数

package zuoye.bdqn.demo;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;


public class Student {
public static void main(String[] args) {
	Connection conn=null;
	PreparedStatement pstmt=null;
	ResultSet rs=null;
	try {
		Class.forName("com.mysql.jdbc.Driver");
	} catch (ClassNotFoundException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}
	try {
		conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/zuoye?useUnicode=true&characterEncoding=utf-8","root","520");
		pstmt=conn.prepareStatement("insert into student (id,name) values (?,?)");
		pstmt.setInt(1, 1);
		pstmt.setString(2,"黄志豪");
		pstmt.executeUpdate();
		System.out.println("插入成功！");
		rs=pstmt.executeQuery("select count(*)from student");
		while(rs.next()) {
			System.out.println("表*有"+rs.getInt(1)+"条记录");
		}
	} catch (SQLException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}finally {
		if(rs!=null) {
			try {
				rs.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		if(pstmt!=null) {
			try {
				pstmt.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		if(conn!=null) {
			try {
				conn.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
	
}
}

2，查询student表所有记录，并在控制台输出数据

package zuoye.bdqn.demo;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

public class student1 {
		public static void main(String[] args) {
		Connection conn = null;
		Statement st = null;
		ResultSet rs = null;
		try {
		Class.forName("com.mysql.jdbc.Driver");
		conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/zuoye","root","520");
		st= conn.createStatement();
		rs=st.executeQuery("select * from student");
		while(rs.next()) {
        System.out.println("序号："+rs.getInt("id")+"姓名："+rs.getString("name"));
		            }
		        } catch (Exception e) {
		e.printStackTrace();
		} finally {
		if(conn!=null) {
        try {
		conn.close();
		} catch (SQLException e) {
          e.printStackTrace();
		                }
		            }
}
		    }
		}

3，宠物主人根据控制台输入用户名和密码，如果输入正确，输出用户登录成功，否则输出用户登录失败

package zuoye.bdqn.demo;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Scanner;

public class student2 {
   public static void main(String[] args) {
	 Connection conn=null;
	 PreparedStatement pstmt=null;
	 ResultSet rs=null;
	 Scanner in=new Scanner(System.in);
	 System.out.println("\t宠物主人登录");
	 System.out.println("请输入姓名：");
	 String name=in.next();
	 System.out.println("请输入密码：");
	 String password=in.next();
	 try {
		Class.forName("com.mysql.jdbc.Driver");
	} catch (ClassNotFoundException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}
	 try {
		conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/zuoye?useUnicode=true&characterEncoding=utf-8","root","520");
		String sql="select *from master where name=?and password=?";
		pstmt=conn.prepareStatement(sql);
		pstmt.setString(1, name);
		pstmt.setString(2, password);
		rs=pstmt.executeQuery();
		if(rs.next()) {
			System.out.println("登录成功！");
		}else {
			System.out.println("登录失败！");
		}
	} catch (SQLException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}
		}
}