java代码实现JDBC的增删改查 *** 作（最基础版）

第一步：导入与Mysql版本相匹配的jar包

第二步：编写JDBC 代码

import org.junit.Test;

import java.sql.*;

public class JDBCDemo1 {
    //数据库的查询 *** 作
    @Test
    public void testSelect() {
        Connection conn = null;
        Statement statement = null;
        ResultSet rs = null;
        try {
            //加载数据库驱动
            Class.forName("com.mysql.cj.jdbc.Driver");
            //创建数据库连接
            //url:数据库地址，user：用户名，password：密码
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/db_wwq","root","root");
            //编写查询语句
            String sql = "select * from dept";

            statement = conn.createStatement();
            rs = statement.executeQuery(sql);
            while(rs.next()){
                int deptno = rs.getInt("deptno");
                String dename = rs.getString("dname");
                String loc = rs.getString("loc");
                System.out.println("deptno = " + deptno);
                System.out.println("dename = " + dename);
                System.out.println("loc = " + loc);
            }


        } catch (ClassNotFoundException | SQLException e) {
            e.printStackTrace();
        }finally {

            try {
                rs.close();
                statement.close();
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }

        }
    }




    //数据库的添加 *** 作
    @Test
    public void addMysql(){
        Connection conn = null;
        Statement statement = null;
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/db_wwq","root","root");
            String sql = "INSERT INTO stu VALUES ('S_1012','baba',18,'male') ";
            statement = conn.createStatement();
            int row = statement.executeUpdate(sql);
            System.out.println("row = " + row);
        } catch (ClassNotFoundException | SQLException e) {
            e.printStackTrace();
        }finally {

            try {
                statement.close();
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

    }



    //数据库的修改 *** 作
    @Test
    public void  updateMysql() {
        Connection conn = null;
        Statement statement = null;
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/db_wwq", "root", "root");
            String sql = "UPDATE stu SET sname='diedie' WHERE sid='S_1012'";
            statement = conn.createStatement();
            int row = statement.executeUpdate(sql);
            System.out.println("row = " + row);
        } catch (ClassNotFoundException | SQLException e) {
            e.printStackTrace();
        } finally {

            try {
                statement.close();
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }





    //数据库的删除 *** 作
    @Test
    public void  deleteMysql() {
        Connection conn = null;
        Statement statement = null;
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/db_wwq", "root", "root");
            String sql = "DELETE FROM stu WHERE sname='diedie'";
            statement = conn.createStatement();
            int row = statement.executeUpdate(sql);
            System.out.println("row = " + row);
        } catch (ClassNotFoundException | SQLException e) {
            e.printStackTrace();
        } finally {

            try {
                statement.close();
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}