用java写 JDBC 连接数据库且 增删改查

创建实体类

package com.kjzz;

public class BaseDao {
    private  int  BookID;
    private String  BookName;
    private int TypeID;
    private Double Price;
    private String Publish;
    private String StateID;

    public BaseDao(){

    }
    public BaseDao(int bookID, String bookName, int typeID, Double price, String publish, String stateID) {
        BookID = bookID;
        BookName = bookName;
        TypeID = typeID;
        Price = price;
        Publish = publish;
        StateID = stateID;
    }

    public int getBookID() {
        return BookID;
    }

    public void setBookID(int bookID) {
        BookID = bookID;
    }

    public String getBookName() {
        return BookName;
    }

    public void setBookName(String bookName) {
        BookName = bookName;
    }

    public int getTypeID() {
        return TypeID;
    }

    public void setTypeID(int typeID) {
        TypeID = typeID;
    }

    public Double getPrice() {
        return Price;
    }

    public void setPrice(Double price) {
        Price = price;
    }

    public String getPublish() {
        return Publish;
    }

    public void setPublish(String publish) {
        Publish = publish;
    }

    public String getStateID() {
        return StateID;
    }

    public void setStateID(String stateID) {
        StateID = stateID;
    }



    @Override
    public String toString() {
        return "BaseDao{" +
                "BookID=" + BookID +
                ", BookName='" + BookName + '\'' +
                ", TypeID=" + TypeID +
                ", Price=" + Price +
                ", Publish='" + Publish + '\'' +
                ", StateID='" + StateID + '\'' +
                '}';
    }
}

连接数据库

package com.kjzz;

import java.sql.*;

public class DBUtils {
    public static String DRIVER = "com.mysql.jdbc.Driver";
    public static String URl = "jdbc:mysql://localhost:3306/book";
    public static String USER = "root";
    public static String PWd = "root";

    //加载驱动
    static {
        try {
            Class.forName(DRIVER);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }

    //连接方法
    public static Connection Connection() {
        Connection conn = null;
        try {
            conn = DriverManager.getConnection(URl, USER, PWd);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }

    //测试
    public static void main(String[] args) {
        Connection conn = Connection();
        System.out.println("连接对象是"+conn);
    }


    //关闭
    public static void CloseConn(Connection conn, PreparedStatement prep, ResultSet rs) {
        try {
            if (conn != null) {
                conn.close();
            }
            if (prep != null) {
                prep.close();
            }
            if (rs != null) {
                rs.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

增删改查的运用

package com.kjzz;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class ZSGC {
    public static Connection conn = null;
    public static PreparedStatement prep = null;
    public static ResultSet rs = null;
//查询
    public List ChaXun(){
        List list = new ArrayList<>();
        String SelectSql = "select * from ok";
        try {
            conn = DBUtils.Connection();
            prep = conn.prepareStatement(SelectSql);
            rs = prep.executeQuery();//查询返回的结果集

            while (rs.next()){
                BaseDao dao = new BaseDao();
                int BookID = rs.getInt("BookID");
                String BookName = rs.getString("BookName");
                int TypeID = rs.getInt("TypeID");
                Double Price = rs.getDouble("Price");
                String Publish =rs.getString("Publish");
                String StateID =rs.getString("StateID");
                 dao = new BaseDao(BookID, BookName, TypeID, Price, Publish, StateID);
                 list.add(dao);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return list;
    }
    //增加
    public static boolean Insert(BaseDao dao) {
        int num = 0;
        String InsetSql = "insert into ok values (?,?,?,?,?,?)";
        try {
           conn = DBUtils.Connection();
            prep = conn.prepareStatement(InsetSql);
            prep.setInt(1,dao.getBookID());
            prep.setString(2,dao.getBookName());
            prep.setInt(3,dao.getBookID());
            prep.setDouble(4,dao.getPrice());
            prep.setString(5,dao.getPublish());
            prep.setString(6,dao.getStateID());
             num = prep.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return num > 0;
    }
    //删除
    public static boolean Delete(int BookID){
        int num =0;
        String DeleteSql = "Delete from ok where BookID=?";
        try {
            conn=DBUtils.Connection();
            prep=conn.prepareStatement(DeleteSql);
            prep.setInt(1,BookID);
            num = prep.executeUpdate();
        }catch (SQLException e){
            e.printStackTrace();
        }
        return num > 0;
    }
    //修改
    public static boolean Update(BaseDao dao){
        int num =0;
        String UpdateSql ="update ok set BookName = ?,TypeID=?,Price =?,Publish =?,StateID=? where BookID =?";
    try {
        conn = DBUtils.Connection();
        prep = conn.prepareStatement(UpdateSql);
        prep.setString(1,dao.getBookName());
        prep.setInt(2,dao.getTypeID());
        prep.setDouble(3,dao.getPrice());
        prep.setString(4,dao.getPublish());
        prep.setString(5,dao.getStateID());
        prep.setInt(6,dao.getBookID());
        num = prep.executeUpdate();
    } catch (SQLException e){
        e.printStackTrace();
    }
    return num >0;
    }

}

测试

package com.kjzz;

import org.junit.Test;
import java.util.List;

public class Test01 {
    @Test
    public void test01(){
//        增加
        BaseDao dao = new BaseDao(66,"节",1001,2456.0,"成都府","接触");
         ZSGC.Insert(dao);
    }

    @Test
//查询
    public void test02(){
        ZSGC zsgc = new ZSGC();
        List list = zsgc.ChaXun();
        for (BaseDao dao : list){
            System.out.println(dao.getBookID()+" ");
            System.out.println(dao.getBookName()+" ");
            System.out.println(dao.getTypeID()+" ");
            System.out.println(dao.getPrice()+" ");
            System.out.println(dao.getPublish()+" ");
            System.out.println(dao.getStateID()+" ");
        }
    }
    @Test
    //删除
    public void test03(){
        boolean Delete = ZSGC.Delete(1);
    }

    @Test
    //修改
    public void test05() {
        BaseDao Dao2 = new BaseDao();
        Dao2.setBookID(66);
        Dao2.setBookName("胡杨");
        Dao2.setTypeID(0000);
        Dao2.setPrice(0.0);
        Dao2.setPublish("美国出版");
        Dao2.setStateID("接触");
        boolean update = ZSGC.Update(Dao2);
    }

    }