通过idea连接数据库，实现数据库的添加、删除和检查。

import java.sql.*;  public class DBUtil { 
             public static Connection getConnection() throws ClassNotFoundException, SQLException { 
                 Class.forName("com.mysql.jdbc.Driver");         Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/wzsxy","root","123456");         return connection;     }      public static void closeAll(ResultSet resultSet, Statement statement,Connection connection) throws SQLException { 
                 if (resultSet!=null){ 
                     resultSet.close();         }         if (statement!=null){ 
                     statement.close();         }         if (connection!=null){ 
                     connection.close();         }     } } 

import com.xsj.util.DBUtil; import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;

public class Insert { 
        
    public static void main(String[] args) throws ClassNotFoundException, SQLException { 
        
        Connection connection = DBUtil.getConnection();
        System.out.println("创建连接成功");
        String sql = "insert into tb_user values (null, 'yzr', '123')";
        PreparedStatement statement = connection.prepareStatement(sql);
        statement.executeUpdate();

        DBUtil.closeAll(null, statement, connection);
    }
}

import com.xsj.util.DBUtil;

import java.sql.*;

public class Delete { 
        
    public static void main(String[] args) throws ClassNotFoundException, SQLException { 
        
        Connection connection = DBUtil.getConnection();
        System.out.println("创建连接成功");
        String sql = "delete from tb_user where id=3";
        PreparedStatement statement = connection.prepareStatement(sql);
        statement.executeUpdate();

        DBUtil.closeAll(null,statement,connection);
    }
}

import com.xsj.util.DBUtil;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;


public class Update { 
        
    public static void main(String[] args) throws ClassNotFoundException, SQLException { 
        
        Connection connection = DBUtil.getConnection();
        System.out.println("创建连接成功");
        String sql = "update tb_user set username = 'xsj' where id = 1";
        PreparedStatement statement = connection.prepareStatement(sql);
        statement.executeUpdate();

        DBUtil.closeAll(null,statement,connection);
    }
}

import com.xsj.util.DBUtil;

import java.sql.*;

public class Find { 
        
    public static void main(String[] args) throws ClassNotFoundException, SQLException { 
        
        Connection connection = DBUtil.getConnection();
        String sql = "select * from tb_user";
        PreparedStatement statement = connection.prepareStatement(sql);
        ResultSet resultSet = statement.executeQuery();
        while(resultSet.next()){ 
        
            System.out.println(resultSet.getInt(1));
            System.out.println(resultSet.getString(2));
            System.out.println(resultSet.getString(3));
        }
        DBUtil.closeAll(resultSet,statement,connection);
    }
}