python - 如何使用pycharm连接spark和mysql

Question

我尝试从 mysql 数据库中选择表内容到数据框， 我按照以下步骤将 Spark 与 mysql 连接起来。

1. 下载mysql-connector-java-5.0.8-bin.jar
2. 我输入mysql-connector-java-5.0.8-bin.jar在路径 $SPARK_HOME/bin/mysql-connector-java-5.0.8-bin.jar 但它仍然不起作用

代码:

from pyspark import SparkContext
from pyspark.sql import SQLContext, Row

sc = SparkContext()
sqlctx = SQLContext(sc)


 dataframe_mysql = sqlctx.read.format("jdbc").options(
    url="jdbc:mysql://localhost:3306/database",
    driver="com.mysql.jdbc.Driver",
    dbtable="user",
    user="root",
    password="").load()

之后我尝试使用cmd将spark与mysql连接 使用 –jars 参数启动 pyspark shell

$SPARK_HOME/bin/pyspark  –-jars mysql-connector-java-5.0.8-bin.jar

也不起作用 我不明白为什么使用 driver="com.mysql.jdbc.Driver" 连接到 mysql 谁能帮我 提前致谢

我收到这个错误

File "C:/Users/kcs/PycharmProjects/Flunky/SparkMySql.py", line 14, in <module>
  password="").load()
  File "C:\DataScience\python\pyspark\sql\readwriter.py", line 123, in load
  return self._df(self._jreader.load())
  File "C:\DataScience\python\lib\py4j-0.8.2.1-          src.zip\py4j\java_gateway.py", line 538, in __call__
  File "C:\DataScience\python\pyspark\sql\utils.py", line 36, in deco
   return f(*a, **kw)
   File "C:\DataScience\python\lib\py4j-0.8.2.1-src.zip\py4j\protocol.py",     line 300, in get_return_value
 py4j.protocol.Py4JJavaError: An error occurred while calling o24.load.
 : java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at org.apache.spark.sql.execution.datasources.jdbc.DriverRegistry$.register(DriverRegistry.scala:38)
at org.apache.spark.sql.execution.datasources.jdbc.DefaultSource.createRelation(DefaultSource.scala:41)
at org.apache.spark.sql.execution.datasources.ResolvedDataSource$.apply(ResolvedDataSource.scala:125)
at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:114)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:231)
at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:379)
at py4j.Gateway.invoke(Gateway.java:259)
at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:133)
at py4j.commands.CallCommand.execute(CallCommand.java:79)
at py4j.GatewayConnection.run(GatewayConnection.java:207)
at java.lang.Thread.run(Unknown Source)

and the error on cmd is

Answer 1

看看你下载了 mysql-connector-java-5.0.8-bin.jar 并在你的代码中启动 shell $SPARK_HOME/bin/pyspark –-jars mysql-connector-java-5.1.8-bin.jar您的mysql驱动版本不一样，修复后检查一下即可。