Errors when creating a Value and Timestamp dataframe with Azure Databricks - apache-spark

Question

I'm not too familiar with Spark but I'm forced to use it to consume some data. I've tried basically every syntax I could find to make a dataframe with a value and a timestamp that I can put into a database to track when I get updates from the datasource. The errors are endless and I'm out of ideas and short on reasons for why I can't make something this simple. Below is the sample of code I'm trying to get working
sc = spark.sparkContext
df = sc.parallelize([[1,pyspark.sql.functions.current_timestamp()]]).toDF(("Value","CreatedAt"))
and this error doesn't really help
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()
I've also tried this
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
)
With the error
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())

Answer 1

Well I code something to work eventually. I couldn't get it to work with TimestampType() though, spark would flip out when inserting the data. I think that may be a runtime error and not a coding issue though.
import adal
import datetime;
from pyspark.sql.types import *
# Set Access Token
access_token = token["accessToken"]
from pyspark.sql import SQLContext
sqlContext = SQLContext(sc) # sc is the spark context
schema = StructType([
StructField("CreatedAt", StringType(), True),
StructField("value", StringType(), True)
])
da = datetime.datetime.now().strftime("%m/%d/%Y %H:%M:%S")
df = sqlContext.createDataFrame(
[(da,'12a345')],schema
)
df.write \
.format("com.microsoft.sqlserver.jdbc.spark") \
.option("url", url)\
.option("dbtable", "dbo.RunStart")\
.option("accessToken", access_token)\
.option("databaseName", database_name) \
.option("encrypt", "true")\
.option("hostNameInCertificate", "*.database.windows.net")\
.option("applicationintent", "ReadWrite") \
.mode("append") \
.save()