java怎么调用mysql数据库连接

发布网友发布时间：2022-05-07 07:12

共3个回答

懂视网时间：2022-05-07 11:33

mysqljava数据库

比如用户注册，要怎么调用数据库里面的数据以此来判断用户名有没有被注册

热心网友时间：2022-05-07 08:41

package wb;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.Random;

public class Connect {

    String DBDRIVER="com.mysql.jdbc.Driver";
    String DBURL="jdbc:mysql://localhost:3306/test";
    String DBUSER="root";
    String DBPWD="1995nian";
    Connection conn=null;

    public Connect(){
        try {
            Class.forName(DBDRIVER);
            conn=DriverManager.getConnection(DBURL,DBUSER,DBPWD);
            //System.out.println("数据库连接成功");
        } catch (ClassNotFoundException e) {
            // TODO: handle exception
            e.printStackTrace();
        } catch (SQLException e) {
            // TODO: handle exception
            e.printStackTrace();
        }
    }

    public Connection getCon(){
        return conn;
    }

    public void doSql(double x,double y){
        Connection connection=new Connect().getCon();
        try {
            String sql="insert into tmp values(?,?)";
            PreparedStatement ps=connection.prepareStatement(sql);
            ps.setDouble(1, x);
            ps.setDouble(2, y);
            ps.execute();
            ps.close();
            connection.close();
        } catch (Exception e) {
            // TODO: handle exception
        }
    }

    public void closeCon(){
        try{
            conn.close();
        }catch(SQLException e){
            e.printStackTrace();
        }
    }
    public static void main(String[] args){
        Connect connect=new Connect();
        Connection connection=connect.getCon();
        //String sql="insert into tmp values(30,50)";
        connect.doSql(30, 50);
    }
}

这是样板，项目还要引入mysql的数据库驱动

热心网友时间：2022-05-07 09:59

https://zhidao.baidu.com/question/264734748166047805.html?fr=iks&word=java+mysql%CA%FD%BE%DD%BF%E2&ie=gbk

https://zhidao.baidu.com/question/458666899.html?fr=iks&word=java+mysql%CA%FD%BE%DD%BF%E2&ie=gbk

两个是可以参考的

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