我不太熟悉spark,但我不得不用它来消耗一些数据。我已经尝试了我能找到的所有语法来创建一个Dataframe,其中包含一个值和一个时间戳,当我从数据源获得更新时,我可以将其放入数据库中进行跟踪。错误是无止境的,我没有想法,也没有理由解释为什么我不能把事情做得这么简单。下面是我尝试使用的代码示例
sc = spark.sparkContext
df = sc.parallelize([[1,pyspark.sql.functions.current_timestamp()]]).toDF(("Value","CreatedAt"))
这个错误并没有真正的帮助
py4j.Py4JException: Method __getstate__([]) does not exist
---------------------------------------------------------------------------
Py4JError Traceback (most recent call last)
<command-1699228214903488> in <module>
29
30 sc = spark.sparkContext
---> 31 df = sc.parallelize([[1,pyspark.sql.functions.current_timestamp()]]).toDF(("Value","CreatedAt"))
/databricks/spark/python/pyspark/context.py in parallelize(self, c, numSlices)
557 return self._jvm.PythonParallelizeServer(self._jsc.sc(), numSlices)
558
--> 559 jrdd = self._serialize_to_jvm(c, serializer, reader_func, createRDDServer)
560
561 return RDD(jrdd, self, serializer)
/databricks/spark/python/pyspark/context.py in _serialize_to_jvm(self, data, serializer, reader_func, createRDDServer)
590 try:
591 try:
--> 592 serializer.dump_stream(data, tempFile)
593 finally:
594 tempFile.close()
我也试过这个
from pyspark.sql import SQLContext
sqlContext = SQLContext(sc) # sc is the spark context
df = sqlContext.createDataFrame(
[( current_timestamp(), '12a345')],
['CreatedAt','Value'] # the row header/column labels should be entered here
)
带着错误
AssertionError: dataType <py4j.java_gateway.JavaMember object at 0x7f43d97c6ba8> should be an instance of <class 'pyspark.sql.types.DataType'>
---------------------------------------------------------------------------
AssertionError Traceback (most recent call last)
<command-2294571935273349> in <module>
33 df = sqlContext.createDataFrame(
34 [( current_timestamp(), '12a345')],
---> 35 ['CreatedAt','Value'] # the row header/column labels should be entered here
36 )
37
/databricks/spark/python/pyspark/sql/context.py in createDataFrame(self, data, schema, samplingRatio, verifySchema)
305 Py4JJavaError: ...
306 """
--> 307 return self.sparkSession.createDataFrame(data, schema, samplingRatio, verifySchema)
308
309 @since(1.3)
/databricks/spark/python/pyspark/sql/session.py in createDataFrame(self, data, schema, samplingRatio, verifySchema)
815 rdd, schema = self._createFromRDD(data.map(prepare), schema, samplingRatio)
816 else:
--> 817 rdd, schema = self._createFromLocal(map(prepare, data), schema)
818 jrdd = self._jvm.SerDeUtil.toJavaArray(rdd._to_java_object_rdd())
1条答案
按热度按时间krugob8w1#
好吧,我最终会编写一些代码。不过,我无法让它与timestamptype()一起工作,在插入数据时,spark会跳转。我认为这可能是运行时错误,而不是编码问题。