import java.sql.*;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @description:clickhouse连接测试
 * @author: ZhiWen
 * @create: 2021-01-05
 **/
public class ClickhouseUse {


    public static void main(String[] args) {
        //todo 如果连接拒绝 在配置里打开外网访问 <listen_host>::</listen_host>
        String sql = "select count(*) count from tb_user";
        String address = "jdbc:clickhouse://172.24.103.4:8123/default";
        Connection connection = null;
        Statement statement = null;
        ResultSet results = null;
        try {
            Class.forName("ru.yandex.clickhouse.ClickHouseDriver");
            connection = DriverManager.getConnection(address,"default","123456");
            statement = connection.createStatement();
            results = statement.executeQuery(sql);
            ResultSetMetaData rsmd = results.getMetaData();
            List<Map> list = new ArrayList();
            while (results.next()) {
                Map map = new HashMap();
                for (int i = 1; i <= rsmd.getColumnCount(); i++) {
                    map.put(rsmd.getColumnName(i), results.getString(rsmd.getColumnName(i)));
                }
                list.add(map);
            }
            for (Map map : list) {
                System.err.println(map);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (results != null) {
                    results.close();
                }
                if (statement != null) {
                    statement.close();
                }
                if (connection != null) {
                    connection.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    /*create table tb_user(
            uid Int32,
            name String,
            age UInt32,
            gender String
    )engine = TinyLog;*/


}