使用PySpark从MariaDB读取查询

Question

我正在尝试从MariaDB读取查询结果到pyspark数据框。我用过的罐子是

--jars mariadb-java-client-2.2.2.jar

我可以使用]读取表格>

df = spark.read.format("jdbc")\
        .option("url","jdbc:mariadb://xxx.xxx.xx.xx:xxxx/hdpms")\
        .option("driver", "org.mariadb.jdbc.Driver")\
        .option("dbtable", Mytable)\
        .option("user", "xxxxx_xxxxx")\
        .option("password", "xxxxx")\
        .load()
现在我正在寻找一个命令来运行一个简单的查询，例如

SELECT col1,col2,col3,.. From MyTable Where date>2019 and cond2;
尽管我可以通过使用以下命令来运行它：>
"MyTable date>2019 and cond2 --"
因为jar在开头添加SELECT * FROM，在结尾添加where 1=0但我面临以下错误
    py4j.protocol.Py4JJavaError: An error occurred while calling o455.showString.
: org.apache.spark.SparkException: Job aborted due to stage failure: Task 0 in stage 3.0 failed 4 times, most recent failure: Lost task 0.3 in stage 3.0 (TID 12, xhadoopm3095p.aetna.com, executor 2): java.sql.SQLException: Value "DATE_CREATED" cannot be parse as Timestamp
        at org.mariadb.jdbc.internal.com.read.resultset.rowprotocol.TextRowProtocol.getInternalTimestamp(TextRowProtocol.java:592)
        at org.mariadb.jdbc.internal.com.read.resultset.SelectResultSet.getTimestamp(SelectResultSet.java:1178)
        at org.apache.spark.sql.execution.datasources.jdbc.JdbcUtils$$anonfun$org$apache$spark$sql$execution$datasources$jdbc$JdbcUtils$$makeGetter$11.apply(JdbcUtils.scala:439)
        at org.apache.spark.sql.execution.datasources.jdbc.JdbcUtils$$anonfun$org$apache$spark$sql$execution$datasources$jdbc$JdbcUtils$$makeGetter$11.apply(JdbcUtils.scala:438)
任何人都可以帮我这个忙。谢谢

我正在尝试从MariaDB读取查询结果到pyspark数据框。我使用的jar是--jars mariadb-java-client-2.2.2.jar我能够使用df = spark.read.format（“ jdbc”）...读取表。

Answer 1

df = spark.read.format("jdbc")\
        .option("url","jdbc:mariadb://xxx.xxx.xx.xx:xxxx/hdpms")\
        .option("driver", "org.mariadb.jdbc.Driver")\
        .option("dbtable", "(SELECT col1,col2,col3,.. From MyTable Where date>2019 and cond2) tmp")\
        .option("user", "xxxxx_xxxxx")\
        .option("password", "xxxxx")\
        .load()

使用查询为表创建别名，它将起作用