Spark JDBC MySQL 语法错误，列名带有空格

Question

我正在使用 PySpark JDBC 查询一个 MySQL 表。我面临的问题是该表的列名带有空格。

在 MySQL Workbench 中，我会执行这样的查询来获取数据并且效果很好。

select
    `some id`
from
    table

但是当我像这样通过 PySpark 这样做时：

query = 'select `some id` from table'

df = sqlContext.read.format('jdbc') \
        .options(
        driver = 'com.mysql.jdbc.Driver'
        , url = some_connection_url
        , dbtable = query 
        , user = user
        , password = password
    ).load()

我收到以下错误消息：

Py4JJavaError: An error occurred while calling o497.load.
: java.sql.SQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'select
    `some id`
from 
    some_table WHERE 1=0' at line 1
    at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:120)
    at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97)
    at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:122)
    at com.mysql.cj.jdbc.ClientPreparedStatement.executeInternal(ClientPreparedStatement.java:953)
    at com.mysql.cj.jdbc.ClientPreparedStatement.executeQuery(ClientPreparedStatement.java:1003)
    at org.apache.spark.sql.execution.datasources.jdbc.JDBCRDD$.resolveTable(JDBCRDD.scala:61)
    at org.apache.spark.sql.execution.datasources.jdbc.JDBCRelation$.getSchema(JDBCRelation.scala:210)
    at org.apache.spark.sql.execution.datasources.jdbc.JdbcRelationProvider.createRelation(JdbcRelationProvider.scala:35)
    at org.apache.spark.sql.execution.datasources.DataSource.resolveRelation(DataSource.scala:318)
    at org.apache.spark.sql.DataFrameReader.loadV1Source(DataFrameReader.scala:223)
    at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:211)
    at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:167)
    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:748)

我尝试使用 [] 和 "" 引用列名，但收到相同的错误消息。

我还在使用最新的 MySQL jar：mysql-connector-java-8.0.21.jar 和 Spark 2.4。

高度赞赏任何见解。

Answer 1

将您的查询括在括号()中，然后尝试传递给read.format("jdbc")。

示例：

query = '(select `some id` from table)e'

df = sqlContext.read.format('jdbc') \
        .options(
        driver = 'com.mysql.jdbc.Driver'
        , url = some_connection_url
        , dbtable = query 
        , user = user
        , password = password
    ).load()