运行SQL查询时出现PySpark错误

时间:2018-07-26 08:45:20

标签: python pyspark

由于缺乏在pyspark / python中编写代码的知识,我决定在spark.sql中编写查询。我用两种格式编写了查询。第一种格式允许EOL中断。但是,以这种格式,我会看到错误,如下所示:

results5 = spark.sql("SELECT\
  appl_stock.Open\
 ,appl_stock.Close\
FROM appl_stock\
WHERE appl_stock.Close < 500")

以上格式会产生以下错误:

---------------------------------------------------------------------------
Py4JJavaError                             Traceback (most recent call last)
~/spark-2.1.0-bin-hadoop2.7/python/pyspark/sql/utils.py in deco(*a, **kw)
     62         try:
---> 63             return f(*a, **kw)
     64         except py4j.protocol.Py4JJavaError as e:

~/spark-2.1.0-bin-hadoop2.7/python/lib/py4j-0.10.4-src.zip/py4j/protocol.py in get_return_value(answer, gateway_client, target_id, name)
    318                     "An error occurred while calling {0}{1}{2}.\n".
--> 319                     format(target_id, ".", name), value)
    320             else:

Py4JJavaError: An error occurred while calling o19.sql.
: org.apache.spark.sql.catalyst.parser.ParseException: 
mismatched input '.' expecting {<EOF>, ',', 'FROM', 'WHERE', 'GROUP', 'ORDER', 'HAVING', 'LIMIT', 'LATERAL', 'WINDOW', 'UNION', 'EXCEPT', 'MINUS', 'INTERSECT', 'SORT', 'CLUSTER', 'DISTRIBUTE'}(line 1, pos 35)

== SQL ==
SELECT  appl_stock.Open  appl_stock.CloseFROM appl_stockWHERE appl_stock.Close < 500
-----------------------------------^^^

    at org.apache.spark.sql.catalyst.parser.ParseException.withCommand(ParseDriver.scala:197)
    at org.apache.spark.sql.catalyst.parser.AbstractSqlParser.parse(ParseDriver.scala:99)
    at org.apache.spark.sql.execution.SparkSqlParser.parse(SparkSqlParser.scala:45)
    at org.apache.spark.sql.catalyst.parser.AbstractSqlParser.parsePlan(ParseDriver.scala:53)
    at org.apache.spark.sql.SparkSession.sql(SparkSession.scala:592)
    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:280)
    at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
    at py4j.commands.CallCommand.execute(CallCommand.java:79)
    at py4j.GatewayConnection.run(GatewayConnection.java:214)
    at java.lang.Thread.run(Thread.java:748)


During handling of the above exception, another exception occurred:

ParseException                            Traceback (most recent call last)
<ipython-input-38-4920f7e68c0e> in <module>()
----> 1 results5 = spark.sql("SELECT  appl_stock.Open  appl_stock.CloseFROM appl_stockWHERE appl_stock.Close < 500")

~/spark-2.1.0-bin-hadoop2.7/python/pyspark/sql/session.py in sql(self, sqlQuery)
    539         [Row(f1=1, f2=u'row1'), Row(f1=2, f2=u'row2'), Row(f1=3, f2=u'row3')]
    540         """
--> 541         return DataFrame(self._jsparkSession.sql(sqlQuery), self._wrapped)
    542 
    543     @since(2.0)

~/spark-2.1.0-bin-hadoop2.7/python/lib/py4j-0.10.4-src.zip/py4j/java_gateway.py in __call__(self, *args)
   1131         answer = self.gateway_client.send_command(command)
   1132         return_value = get_return_value(
-> 1133             answer, self.gateway_client, self.target_id, self.name)
   1134 
   1135         for temp_arg in temp_args:

~/spark-2.1.0-bin-hadoop2.7/python/pyspark/sql/utils.py in deco(*a, **kw)
     71                 raise AnalysisException(s.split(': ', 1)[1], stackTrace)
     72             if s.startswith('org.apache.spark.sql.catalyst.parser.ParseException: '):
---> 73                 raise ParseException(s.split(': ', 1)[1], stackTrace)
     74             if s.startswith('org.apache.spark.sql.streaming.StreamingQueryException: '):
     75                 raise StreamingQueryException(s.split(': ', 1)[1], stackTrace)

ParseException: "\nmismatched input '.' expecting {<EOF>, ',', 'FROM', 'WHERE', 'GROUP', 'ORDER', 'HAVING', 'LIMIT', 'LATERAL', 'WINDOW', 'UNION', 'EXCEPT', 'MINUS', 'INTERSECT', 'SORT', 'CLUSTER', 'DISTRIBUTE'}(line 1, pos 35)\n\n== SQL ==\nSELECT  appl_stock.Open  appl_stock.CloseFROM appl_stockWHERE appl_stock.Close < 500\n-----------------------------------^^^\n"

以下代码产生成功的结果,请参见下文:

results6 = spark.sql("SELECT appl_stock.Open ,appl_stock.Close FROM appl_stock WHERE appl_stock.Close < 500")

有人可以让我知道为什么第一个代码不起作用,而第二个代码为什么起作用吗?

欢呼

6 个答案:

答案 0 :(得分:2)

因为您在第一个中使用了\,并且将其作为奇数语法传递给spark。如果要编写多行SQL语句,请使用三引号:

results5 = spark.sql("""SELECT
  appl_stock.Open
 ,appl_stock.Close
FROM appl_stock
WHERE appl_stock.Close < 500""")

答案 1 :(得分:0)

错误消息准确地解释了发生了什么。 FROMWHERE关键字前没有空格。

例如,如果您具有以下数据框:

df = spark.createDataFrame([(490, 495), (499, 505), (510, 499)], ["Open", "Close"])
df.show()
#+----+-----+
#|Open|Close|
#+----+-----+
#| 490|  495|
#| 499|  505|
#| 510|  499|
#+----+-----+

df.createOrReplaceTempView("appl_stock")

如果您更改了代码以在每个\前添加一个空格:

results5 = spark.sql("SELECT \
  appl_stock.Open \
 ,appl_stock.Close \
FROM appl_stock \
WHERE appl_stock.Close < 500")

result5.show()
#+----+-----+
#|Open|Close|
#+----+-----+
#| 490|  495|
#| 510|  499|
#+----+-----+

答案 2 :(得分:0)

就我而言,我遇到了错误mismatched input '*' expecting <EOF>。然后我意识到我正在使用spark.table(而不是spark.sql(。我认为这对某人可能有用...

答案 3 :(得分:0)

如果出现类似|的多余字符,则会引发类似的错误消息在SQL查询字符串中。

答案 4 :(得分:0)

怪诞的是,如果我用;终止了我的SQL语句,这对我来说是抛出的。只需将其修复即可。

spark.sql("""
SELECT * FROM foo WHERE bar = 3;
""")

休息。

spark.sql("""
SELECT * FROM foo WHERE bar = 3
""")

没有。

答案 5 :(得分:0)

另一个令人惊讶的情况:我收到了同样风格的错误,即 mismatched input 'from' expecting <EOF>。我的查询包含一个参数,但我忘记解析它(请注意缺少初始 f):

# failing query
my_qry = """
create table my_tab as 
select columns 
from source_tab
where somecolumn < {parameter}
"""
spark.sql(qry_defaults).collect()

所以解决方案是正确解析参数(注意初始的f):

# correct query
my_qry = f"""
create table my_tab as 
select columns 
from source_tab
where somecolumn < {parameter}
"""
spark.sql(qry_defaults).collect()

总而言之,就我而言,错误与缺少 EOF 无关。我希望有人觉得这有帮助。