数据库java操作

1

package data;

import java.sql.*;

import java.sql.*;


public class Operate {
	Connection conn=null;
	Statement stmt=null;
	ResultSet rs=null;
	public String getPass(String name) {
		String name1=null;
		try {
			Connect connect = new Connect();
			conn=connect.getconnect();
			//System.out.println(conn);
			stmt=conn.createStatement();
			String sq1 = "select password from User where user_Name='"+name+"'";
			rs = stmt.executeQuery(sq1);
			rs.next();
			name1=rs.getString(1);
			System.out.println(name1);
			return "OJBK";
		}catch (SQLException e) {System.out.println("OOP!");}
		return "OKOK";
	}

//=====================================================

public boolean borrow(int bookid,int userid) {
		//	String name1=null;
			int t = 0;
			try {
				Connect connect = new Connect();
				conn=connect.getconnect();
				//System.out.println(conn);
				stmt=conn.createStatement();
				String sq1 = "insert into borrow(book_Id,user_Id) value("+bookid+
						","+userid+")";
				t = stmt.executeUpdate(sq1);
				return true;
			}catch (SQLException e) {System.out.println("OOP!");}
			if (t==0) {return true;}
			else
			return false;
		}
//=====================================================

public boolean rebook(int bookid) {
	//	String name1=null;
		int t = 0;
		try {
			Connect connect = new Connect();
			conn=connect.getconnect();
			//System.out.println(conn);
			stmt=conn.createStatement();
			String sq1 = "update borrow set r_Time=now() "+
			 "where book_Id='"+bookid+"'";
			t = stmt.executeUpdate(sq1);
			return true;
		}catch (SQLException e) {System.out.println("OOP!");}
		if (t==0) {return true;}
		else
		return false;
	}
//=====================================================
public double getamount(int bookid) {
	//	String name1=null;
		int t = 0;
		String name1=null;
		double amount=0;
		try {
			Connect connect = new Connect();
			conn=connect.getconnect();
			//System.out.println(conn);
			stmt=conn.createStatement();
			String sq1 = "select timestampdiff(day,b_Time,r_Time) from borrow"+
			" where book_Id='"+bookid+"'";
			rs = stmt.executeQuery(sq1);
			rs.next();
			name1=rs.getString(1);
			System.out.println(name1);
			amount=Double.parseDouble(name1)*0.1;
			
		}catch (SQLException e) 
		{System.out.println("OOP!");}
	return amount;	
	}
//=====================================================
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Operate op = new Operate();
		op.getPass("cui");
		op.borrow(3, 2);
		op.rebook(3);
		System.out.println("hello");
		System.out.println(op.getamount(3));
	}

}

2

package data;

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

public class Connect {

	public final String ver = "com.mysql.jdbc.Driver";
	public final String url = "jdbc:mysql://localhost:3306/book";
	public final String user = "root";
	public final String pass = "rootroot";
	Connection conn = null;
	Statement stmt = null;

	public Connection getconnect() {
		try {
			Class.forName(ver);
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}
		try {
			conn = DriverManager.getConnection(url, user, pass);
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return (conn);
	}
}

3

package data;

import java.sql.*;

import java.sql.*;


public class Operate {
	Connection conn=null;
	Statement stmt=null;
	ResultSet rs=null;
	public String getPass(String name) {
		String name1=null;
		try {
			Connect connect = new Connect();
			conn=connect.getconnect();
			//System.out.println(conn);
			stmt=conn.createStatement();
			String sq1 = "select password from User where user_Name='"+name+"'";
			rs = stmt.executeQuery(sq1);
			rs.next();
			name1=rs.getString(1);
			System.out.println(name1);
			return "OJBK";
		}catch (SQLException e) {System.out.println("OOP!");}
		return "OKOK";
	}

//=====================================================

public boolean borrow(int bookid,int userid) {
		//	String name1=null;
			int t = 0;
			try {
				Connect connect = new Connect();
				conn=connect.getconnect();
				//System.out.println(conn);
				stmt=conn.createStatement();
				String sq1 = "insert into borrow(book_Id,user_Id) value("+bookid+
						","+userid+")";
				t = stmt.executeUpdate(sq1);
				return true;
			}catch (SQLException e) {System.out.println("OOP!");}
			if (t==0) {return true;}
			else
			return false;
		}
//=====================================================
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Operate op = new Operate();
		op.getPass("cui");
		op.borrow(1, 2);
	}

}