JDBC上，

JDBC上，

1.JDBC ：java database connection java数据连接，用java代码连接数据库

package jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class Test {

public static void main(String[] args) {
	//加载驱动
	try {
		Class.forName("com.mysql.jdbc.Driver");
	} catch (ClassNotFoundException e) {
		e.printStackTrace();
	}
	//建立java与MySQL数据库连接
	try {
		Connection connection = DriverManager.getConnection("jdbc:mysql://101.200.43.31:3306/venus", "root", "root");
		System.out.println(connection);
	} catch (SQLException e) {
		e.printStackTrace();
	}		
}

}
执行后出现
则代表已经连接上数据库

2.修改数据（添加，修改，删除）

package jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;

public class Test {

public static void main(String[] args) {
	//加载驱动
	try {
		Class.forName("com.mysql.jdbc.Driver");
	} catch (ClassNotFoundException e) {
		e.printStackTrace();
	}
	Connection connection = null;
	Statement statement = null;
	//建立java与MySQL数据库连接
	try {
		connection = DriverManager.getConnection("jdbc:mysql://101.200.43.31:3306/venus", "root", "root");
		statement = connection.createStatement();//相当于打开了修改的窗口
		int rows = statement.executeUpdate("delete from student");//此时执行相当于点了run
		//修改数据(insert,delete,update)
		if(rows>0) {
			System.out.println("yes");
		}else {
			System.out.println("no");
		}
	} catch (SQLException e) {
		e.printStackTrace();
	}finally {
		//释放资源讲求顺序，要倒着来
		try {
			if (statement!=null) {
				statement.close();
			}//不加if如果为空会报空指针异常
		} catch (SQLException e) {
			e.printStackTrace();
		}
		try {
			if (connection!=null) {
				connection.close();
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}		
}

 }

封装方法：

public static void main(String[] args) {
	String id = UUID.randomUUID().toString();
	String sql = "insert into student(id,user_name,password) values ('"+id+"','admin','root') ";
  	
	if (update(sql)) {
		System.out.println(1);
	}else {
		System.out.println(0);
	}
}

public static boolean update(String sql) {
	//加载驱动
	try {
		Class.forName("com.mysql.jdbc.Driver");
	} catch (ClassNotFoundException e) {
		e.printStackTrace();
	}
	Connection connection = null;
	Statement statement = null;
	//建立java与MySQL数据库连接
	try {
		connection = DriverManager.getConnection("jdbc:mysql://101.200.43.31:3306/venus", "root", "root");
		statement = connection.createStatement();//相当于打开了修改的窗口
		int rows = statement.executeUpdate(sql);//此时执行相当于点了run
		//修改数据(insert,delete,update)
		return rows>0;
	} catch (SQLException e) {
		e.printStackTrace();
	}finally {
		//释放资源讲求顺序，要倒着来
		try {
			if (statement!=null) {
				statement.close();
			}//不加if如果为空会报空指针异常
		} catch (SQLException e) {
			e.printStackTrace();
		}
		try {
			if (connection!=null) {
				connection.close();
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}
	return true;		
}
}

3.查询数据

package jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class Text {

public static void main(String[] args) {
	try {
		Class.forName("com.mysql.jdbc.Driver");
	} catch (ClassNotFoundException e) {
		e.printStackTrace();
	}
	Connection connection = null;
	Statement statement = null;
	ResultSet resultSet = null ; 
	try {
		connection = DriverManager.getConnection("jdbc:mysql://101.200.43.31:3306/venus", "root", "root");
		statement = connection.createStatement();	
		resultSet = statement.executeQuery("select * from student");
		while(resultSet.next()) {
			String id = resultSet.getString("id");
			System.out.println(id);
		}
	} catch (SQLException e) {
		e.printStackTrace();
	}finally {
		try {
			if (resultSet!=null) {
				resultSet.close();
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		try {
			if (statement!=null) {
				statement.close();
			}//不加if如果为空会报空指针异常
		} catch (SQLException e) {
			e.printStackTrace();
		}
		try {
			if (connection!=null) {
				connection.close();
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}		 
}
}