在cassandra中读取请求（使用replica 3和一致性ONE）是否返回数据？(Does read request in cassandra (with replica 3 and consistency ONE) return the data?)

 如果您只想显示一个，请使用相关子查询： 
 
select p.*,
       (select ph.url_little
        from ".Constants::$PHOTOS_PRODUCTS_TABLE." ph
        where p.id = ph.id_product
        order by ph.id asc
        limit 1
       ) as url_little
from  ".Constants::$PRODUCTS_TABLE." as p 
where p.id_client = ?;

If you only want to show one, use a correlated subquery:
 
select p.*,
       (select ph.url_little
        from ".Constants::$PHOTOS_PRODUCTS_TABLE." ph
        where p.id = ph.id_product
        order by ph.id asc
        limit 1
       ) as url_little
from  ".Constants::$PRODUCTS_TABLE." as p 
where p.id_client = ?;