數據庫MySQL

數據庫MySQL-20175218

1、題目要求

1. 下載附件中的world.sql.zip, 參考http://www.cnblogs.com/rocedu/p/6371315.html#SECDB，導入world.sql,提交導入成功截圖
2. 編寫程序，查詢世界上超過「你學號前邊七位並把最後一位家到最高位，最高位爲0時置1」（好比學號20165201，超過3016520；學號20165208，超過1016520）的全部城市列表，提交運行結果截圖
3. 編寫程序，查詢世界上的全部中東國家的總人口

4. 編寫程序，查詢世界上的平均壽命最長和最短的國家

   2、實驗程序

   一、getCity

package MySQL;

import java.sql.*;

public class getCity {
    public static void main(String[] args) {
        Connection con;
        Statement sql;
        ResultSet rs;
        con = GetDBConnection.connectDB("world","root","");
        if(con == null) {
            return;
        }
        try {
            sql=con.createStatement();
            rs = sql.executeQuery("SELECT * FROM city");
            while (rs.next()) {
                int ID = rs.getInt(1);
                String Name = rs.getString(2);
                String CountryCode = rs.getString(3);
                String District = rs.getString(4);
                int Population =rs.getInt(5);
                if(Population>1017520) {
                    System.out.printf("%d\t", ID);
                    System.out.printf("%s\t", Name);
                    System.out.printf("%s\t", CountryCode);
                    System.out.printf("%s\t", District);
                    System.out.printf("%d\n", Population);
                }
            }
            con.close();
        }
        catch (SQLException e) {
            System.out.println(e);
        }
    }
}

二、getPopulation

package MySQL;

import java.sql.*;

public class getPopulation {
    public static void main(String[] args) {
        Connection con;
        Statement sql;
        ResultSet rs;
        con = GetDBConnection.connectDB("world","root","");
        if(con == null) {
            return;
        }
        String sqlStr = "select * from country where Region = 'Middle East'";
        try {
            sql = con.createStatement();
            rs = sql.executeQuery(sqlStr);
            long totalpopulation = 0;
            while(rs.next()) {
                int Population = rs.getInt(7);
                totalpopulation +=Population;
            }
            System.out.println("中東國家的總人口爲"+totalpopulation);
            con.close();
        }
        catch (SQLException e) {
            System.out.println(e);
        }
    }
}

三、getlife

package MySQL;
import java.sql.*;
public class getlife {
    public static void main(String[] args) {
        Connection con;
        Statement sql;
        ResultSet rs;
        con = GetDBConnection.connectDB("world","root","");
        if(con == null) {
            return;
        }
        String sqlStr = "select * from country order by LifeExpectancy";
        try {
            sql = con.createStatement();
            rs = sql.executeQuery(sqlStr);
            rs.first();
            String highcountry,lowcountry;
            float number1 = rs.getInt(8);
            while(number1 == 0) {
                rs.next();
                number1 = rs.getInt(8);
            }
            lowcountry = rs.getString(2);
            System.out.println("世界上平均壽命最短的國家爲："+lowcountry+" 壽命爲"+number1);
            rs.last();
            float number2 = rs.getInt(8);
            highcountry = rs.getString(2);
            System.out.println("世界上平均壽命最長的國家爲："+highcountry+" 壽命爲"+number2);
            con.close();
        }
        catch (SQLException e) {
            System.out.println(e);
        }
    }
}

四、GetDBConnection

package MySQL;
import java.sql.*;
public class GetDBConnection {
    public static Connection connectDB(String DBName,String id,String p) {
        Connection con = null;
        String
                uri = "jdbc:mysql://localhost:3306/"+DBName+"?serverTimezone=GMT%2B8&characterEncoding=utf-8";
        try{  Class.forName("com.mysql.cj.jdbc.Driver");//加載JDBC-MySQL驅動
        }
        catch(Exception e){}
        try{
            con = DriverManager.getConnection(uri,id,p); //鏈接代碼
        }
        catch(SQLException e){}
        return con;
    }
}

3、實驗截圖

4、代碼託管

碼雲連接(https://gitee.com/cjy-123/20175218cjy/tree/master/week10/mysql)