使用pyspark连接到MSSQL Server数据库

Question

我是 pyspark 新手，正在尝试连接到 mssql 服务器数据库。详细信息如下： 当我运行我的脚本时，它会被打印出来。

('Processing table:', u'POL_ACTION_AMEND')
('Table schema:', u'dbo')
('Source_database:', u'PRD01_IPS')
('SQL Query:', '(SELECT TOP 100 * FROM PRD01_IPS.dbo.POL_EVENT_HISTORY)')
('jdbc_uri:', 'jdbc:jtds:sqlserver://REPLCLPRD01\REPL/PRD01_IPS')

但是当尝试从表中加载数据时，spark.read.format() 会抛出错误。

select_statement_sql_server = "(SELECT TOP 100 * FROM {source_database}.{schema}.{table_name})"


# Read data for a table 
data_df = (
    spark.read.format("jdbc")
        .option("url",source_jdbc_uri)
        .option("user",source_jdbc_user)
        .option("password",source_jdbc_pass)
        .option("driver", source_jdbc_driver)
        .option("dbtable", select_statement_sql_server.format(
            source_database=source_database, schema=schema, table_name='POL_EVENT_HISTORY'
        ))
        .load()
)
    
data.show()

我收到的错误是：

('SQL Query:', '(SELECT TOP 100 * FROM PRD01_IPS.dbo.POL_EVENT_HISTORY)')
Traceback (most recent call last):
  File "/pkg/lxd0bigd/Talend_To_Pyspark/PSTAR_IPS/200job_IPS.py", line 136, in <module>
    .option("dbtable", select_statement_sql_server.format(source_database=source_database, schema=schema, table_name='POL_EVENT_HISTORY')) \
  File "/opt/cloudera/parcels/CDH-7.1.8-1.cdh7.1.8.p0.30990532/lib/spark/python/lib/pyspark.zip/pyspark/sql/readwriter.py", line 172, in load
  File "/opt/cloudera/parcels/CDH-7.1.8-1.cdh7.1.8.p0.30990532/lib/spark/python/lib/py4j-0.10.7-src.zip/py4j/java_gateway.py", line 1257, in __call__
  File "/opt/cloudera/parcels/CDH-7.1.8-1.cdh7.1.8.p0.30990532/lib/spark/python/lib/pyspark.zip/pyspark/sql/utils.py", line 63, in deco
  File "/opt/cloudera/parcels/CDH-7.1.8-1.cdh7.1.8.p0.30990532/lib/spark/python/lib/py4j-0.10.7-src.zip/py4j/protocol.py", line 328, in get_return_value
py4j.protocol.Py4JJavaError: An error occurred while calling o236.load.
: java.lang.NullPointerException
    at org.apache.spark.sql.execution.datasources.jdbc.JDBCRDD$.resolveTable(JDBCRDD.scala:71)
    at org.apache.spark.sql.execution.datasources.jdbc.JDBCRelation$.getSchema(JDBCRelation.scala:211)
    at org.apache.spark.sql.execution.datasources.jdbc.JdbcRelationProvider.createRelation(JdbcRelationProvider.scala:35)
    at org.apache.spark.sql.execution.datasources.DataSource.resolveRelation(DataSource.scala:332)
    at org.apache.spark.sql.DataFrameReader.loadV1Source(DataFrameReader.scala:243)
    at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:231)
    at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:187)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:244)
    at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:357)
    at py4j.Gateway.invoke(Gateway.java:282)
    at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
    at py4j.commands.CallCommand.execute(CallCommand.java:79)
    at py4j.GatewayConnection.run(GatewayConnection.java:238)
    at java.lang.Thread.run(Thread.java:750)

我有一个shell脚本来运行具有spark-submit命令的脚本。

spark-submit --master yarn --deploy-mode client \
    --driver-class-path ${DRIVER_AND_JAR_FILE_PATH} \
    --jars ${DRIVER_AND_JAR_FILE_PATH},${JAR_FILE_XML} \
    --conf "spark.dynamicAllocation.enabled=true" \
    --conf "spark.yarn.dist.files=/etc/hive/conf.cloudera.hive/hive-site.xml" \
    ${ROOT_DIR}/200job_IPS.py \
    --hdfspath ${XML_FILE_HDFS} >> ${LOGFILE_DIR}/200job_log.txt 2>&1 

sh /pkg/lxd0bigd/Talend_To_Pyspark/PSTAR_IPS/Ingestion_PSTAR.sh dev \
    /pkg/lxd0bigd/Talend_To_Pyspark/spark-jobs/lib/mssql-jdbc-6.2.1.jre7.jar

DRIVER_AND_JAR_FILE_PATH 是我不确定的。我有 3 个 jar 文件，但不知道该使用哪个。我尝试了所有 3 个，也存在同样的问题。

mssql-jdbc-6.2.1.jre7.jar、sqljdbc41.jar、jtds-1.3.1-patch.jar

任何建议和解决方案都会非常有帮助。

Answer 1

我的第一个猜测是您的网址格式错误。不确定那

\REPL

是什么。

尝试：

jdbc:jtds:sqlserver://REPLCLPRD01/PRD01_IPS

或

jdbc:jtds:sqlserver://REPLCLPRD01:<custom-port-if-applicable>/PRD01_IPS

请参阅此答案以供参考。

此外，正如我评论的那样，在这种情况下，

query

选项比

dbtable

更合适。虽然这不是你 NPE 的原因。

.option("query", select_statement_sql_server....)