用java实现 从clickhouse库取数据取网站pv uv信息，自动写到另一个myaql库

可以使用JDBC连接ClickHouse和MySQL数据库，然后使用SQL语句从ClickHouse中查询网站PV和UV信息，将结果写入MySQL数据库中。以下是一个简单的Java代码示例：

import java.sql.*;

public class ClickHouseToMySQL {
    public static void main(String[] args) {
        try {
            // Connect to ClickHouse database
            String clickhouseUrl = "jdbc:clickhouse://localhost:8123/default";
            String clickhouseUser = "default";
            String clickhousePassword = "";
            Connection clickhouseConn = DriverManager.getConnection(clickhouseUrl, clickhouseUser, clickhousePassword);

            // Connect to MySQL database
            String mysqlUrl = "jdbc:mysql://localhost:3306/mydatabase";
            String mysqlUser = "root";
            String mysqlPassword = "password";
            Connection mysqlConn = DriverManager.getConnection(mysqlUrl, mysqlUser, mysqlPassword);

            // Query ClickHouse database
            String clickhouseQuery = "SELECT website, SUM(pv) AS total_pv, SUM(uv) AS total_uv FROM mytable GROUP BY website";
            Statement clickhouseStmt = clickhouseConn.createStatement();
            ResultSet clickhouseRs = clickhouseStmt.executeQuery(clickhouseQuery);

            // Insert into MySQL database
            String mysqlInsert = "INSERT INTO mytable (website, total_pv, total_uv) VALUES (?, ?, ?)";
            PreparedStatement mysqlStmt = mysqlConn.prepareStatement(mysqlInsert);
            while (clickhouseRs.next()) {
                String website = clickhouseRs.getString("website");
                int total_pv = clickhouseRs.getInt("total_pv");
                int total_uv = clickhouseRs.getInt("total_uv");
                mysqlStmt.setString(1, website);
                mysqlStmt.setInt(2, total_pv);
                mysqlStmt.setInt(3, total_uv);
                mysqlStmt.executeUpdate();
            }

            // Close connections
            clickhouseRs.close();
            clickhouseStmt.close();
            clickhouseConn.close();
            mysqlStmt.close();
            mysqlConn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

注意：需要将ClickHouse和MySQL的JDBC驱动程序添加到项目中。