Explanation:
The error in the code block is due to the incorrect use of the sql() method on the DataFrame storesDF. The sql() method is not a DataFrame operation; it is a method of the SparkSession object, typically accessed via the spark variable. After creating a temporary view of the DataFrame with createOrReplaceTempView(), the correct way to execute a SQL query is by using spark.sql(). Therefore, the correct answer is B, as it accurately identifies the misuse of the sql() method on the DataFrame and correctly states that it should be accessed via the spark variable instead. The other options either misrepresent the functionality of createOrReplaceTempView() or incorrectly suggest that SQL cannot be used for this purpose.
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The code block shown below contains an error. The code block is intended to use SQL to return a new DataFrame containing column storeId and column managerName from a table created from DataFrame storesDF. Identify the error.
Code block:
storesDF.createOrReplaceTempView("stores")
storesDF.sql("SELECT storeId, managerName FROM stores")
storesDF.createOrReplaceTempView("stores")
storesDF.sql("SELECT storeId, managerName FROM stores")
A
The createOrReplaceTempView() operation does not make a Dataframe accessible via SQL.
B
The sql() operation should be accessed via the spark variable rather than DataFrame storesDF.
C
There is the sql() operation in DataFrame storesDF. The operation query() should be used instead.
D
This cannot be accomplished using SQL – the DataFrame API should be used instead.
E
The createOrReplaceTempView() operation should be accessed via the spark variable rather than DataFrame storesDF.