Question

我正在尝试做以下事情：

private val preparedFindQuery = session.prepare {
s"""
   |SELECT hash, art_index, operating_system, height, width, resolution, orientation, brand, model, networktype, network, aggcount
   |FROM $keyspace.$table
   |WHERE hash = :hash
   |  AND art_index >= :from_art_index
   |  AND art_index <= :to_art_index
   |  ORDER BY :orderCol :order
 """.stripMargin.trim
}

不幸的是我收到以下错误：

line 6:11 no viable alternative at input ':' (... <= :to_art_index  ORDER BY [:]...)
com.datastax.driver.core.exceptions.SyntaxError: line 6:11 no viable alternative at input ':' (... <= :to_art_index  ORDER BY [:]...)

是否有可能使这项工作成功或者无法以编程方式使用订单？提前致谢

Answer 1

您不能在＆＃39;顺序中使用命名参数。标准因为它需要列名而不是值/绑定标记（？，：name）。您需要在部分准备好的报表中提供您希望订购数据的实际列名，并且BryceAtNetwork23提到某些列不能订购。

Answer 2

您可以基于Lucene框架（只是一个库）创建一个CUSTOM INDEX，然后按照您想要的任何列进行排序，如下例所示：

SELECT * FROM tweets WHERE expr(tweets_index, '{
filter : [ {type: "range", field: "time", lower: "2014/04/25", upper: "2014/05/01"},
           {type: "prefix", field: "user", value: "a"} ],
query : {type: "phrase", field: "body", value: "big data gives organizations", slop: 1},
sort : {field: "time", reverse: true}') limit 100;

在此处查找详情和示例cassandra-lucene-index

如何使用数据存储区驱动程序会话在cassandra中创建带有顺序的cql查询？

2 个答案: