假设下一个Cassandra ColumnFamily:
CREATE TABLE myTable (
A text,
B text,
time timestamp,
PRIMARY KEY ((A, B), time)
) WITH CLUSTERING ORDER BY (time ASC)
AND bloom_filter_fp_chance = 0.01
AND caching = '{"keys":"ALL", "rows_per_partition":"NONE"}'
AND comment = ''
AND compaction = {'min_threshold': '4', 'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy', 'max_threshold': '32'}
AND compression = {'sstable_compression': 'org.apache.cassandra.io.compress.LZ4Compressor'}
AND dclocal_read_repair_chance = 0.1
AND default_time_to_live = 0
AND gc_grace_seconds = 864000
AND max_index_interval = 2048
AND memtable_flush_period_in_ms = 0
AND min_index_interval = 128
AND read_repair_chance = 0.0
AND speculative_retry = '99.0PERCENTILE';
我需要执行下一个CQL 3查询:
SELECT * FROM myTable WHERE A='aaaaa' AND B='bbbbb' ORDER BY time DESC
(通过使用Datastax Driver Mapping(cassandra-driver-mapping-2.1.6)在CQL控制台中可以正常工作) . 我的Accesor是下一个:
@Accessor
public interface myTableAccesor {
@Query("SELECT * FROM myTable WHERE A=:A AND B=:B ORDER BY time :order")
Result<myTable> getAllByKey(@Param("A") String A, @Param("B") String B, @Param("order") String order);
}
但我得到了下一个例外:
java.util.concurrent.ExecutionException: com.datastax.driver.core.exceptions.SyntaxError: line 1:136 missing EOF at ':' (...=:B ORDER BY time [:]order)
当我执行时:
myTableAccesor accessor = manager.createAccessor(myTableAccesor.class);
但是,LIMIT案例:
@Query("SELECT * FROM myTable WHERE A=:A AND B=:B LIMIT :max")
Result<myTable> getAllByKey(@Param("A") String A, @Param("B") String B, @Param("max") String max);
工作正常 .
我认为这个问题与字符串类型有关(也许是某些'字符?)但我不确定 . 有什么方法可以解决这个问题吗?
先感谢您 .
1 回答
不幸的是,在准备语句(这是访问者使用的)中的ORDER BY方向上绑定是无效的CQL,就像使用LIMIT一样 . 作为一种解决方法,您可以创建两个单独的访问器: