cassandra cql查询

cql不支持group by

查询的时候还报错

InvalidRequest: code=2200 [Invalid query] message="Cannot execute this query as it might involve data filtering and thus may have unpredictable performance. If you want to execute this query despite the performance unpredictability, use ALLOW FILTERING"

记录一下，参考此篇
如果你的查询条件里，有一个是根据索引查询，那其它非索引非主键字段，可以通过加一个ALLOW FILTERING来过滤实现
例如：

1
SELECT * FROM test WHERE e=1 AND m>2 ALLOW FILTERING;
虽然m字段是非索引非主键字段，但是只要加了ALLOW FILTERING条件，它会先根据e=1查出来，再对结果进行m>2过滤