Question

我在scala中编写了这个简单的程序来查询cassandra

val session = cass.session
lazy val stmt = cass.session.prepare(
   """
     |select token(id), id, date, rId, tt
     | from foo
     | where token(id) > ?
     | and token(id) <= ?;
   """.stripMargin
)

lazy val statement = stmt.bind().setLong(0, start).setLong(1, end)

def fromRow(row: Row): Foo = {
   val token = row.getLong(0)
   val id = row.getLong(1)
   val date = row.getLong(2)
   val rId = row.getLong(3)
   val tt = row.getInt(4)
   Foo(id, date, rId, tt)
}

但是此代码失败并显示错误

[error] (run-main-4) com.datastax.driver.core.exceptions.CodecNotFoundException: Codec not found for requested operation: [timestamp <-> java.lang.Long]
com.datastax.driver.core.exceptions.CodecNotFoundException: Codec not found for requested operation: [timestamp <-> java.lang.Long]
    at com.datastax.driver.core.CodecRegistry.notFound(CodecRegistry.java:679)
    at com.datastax.driver.core.CodecRegistry.createCodec(CodecRegistry.java:526)
    at com.datastax.driver.core.CodecRegistry.findCodec(CodecRegistry.java:506)
    at com.datastax.driver.core.CodecRegistry.access$200(CodecRegistry.java:140)
    at com.datastax.driver.core.CodecRegistry$TypeCodecCacheLoader.load(CodecRegistry.java:211)
    at com.datastax.driver.core.CodecRegistry$TypeCodecCacheLoader.load(CodecRegistry.java:208)
    at com.google.common.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3542)

Answer 1

根据链接here，将Date类型的var绑定到您的语句：

stmt.bind(new Date(start), new Date(end))

Answer 2

在表FOO中，有一个时间戳类型列，但您将插入查询中的长值传递给该列。您可以将日期列类型定义为时间戳。插入时间戳类型值＆＃39; 2012-12-07T10：00：00-0000＆＃39;看起来像这样。

Answer 3

对于驱动程序v4.0，timestamp被映射到java.time.Instant，因此： stmt.bind(Instant.ofEpochSecond(start), Instant.ofEpochSecond(end))

找不到所请求操作的编解码器：[timestamp＆lt; - ＆gt; java.lang.Long中]

3 个答案: