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Double Slash Comment (U-SQL)

Michael Rys|Last Updated: 5/15/2018
|
4 Contributors

Indicates user-provided text. Comments can be inserted on a separate line, nested at the end of a U-SQL command line, or within a U-SQL statement. The query processor does not evaluate the comment.

Syntax
Double_Slash_Comment :=                                                                             
    '//' text_of_comment.

Semantics of Syntax Elements

  • text_of_comment
    Is the character string that contains the text of the comment.

Use two slashes (//) for single-line or nested comments. Comments inserted with // are terminated by the newline character. There is no maximum length for comments.

Example

  • The example can be executed in Visual Studio with the Azure Data Lake Tools plug-in.
  • The script can be executed locally. An Azure subscription and Azure Data Lake Analytics account is not needed when executed locally.

The following example uses the // commenting characters.

// simple rowset variable
@someBooks = 
    SELECT * FROM 
        ( VALUES
        ("The Book Thief", "Markus Zusak", "2005"),
        ("The Girl with the Dragon Tattoo", "Stieg Larsson", "2005"),
        ("The Silver Linings Playbook", "Matthew Quick", "2008"),
        ("Sarah's Key", "Tatiana de Rosnay", "2006")
        ) AS T(Books, Author, [Publication Year]);

// return books from 2006
@result =
    SELECT *
    FROM @someBooks // this is a nested comment
    WHERE [Publication Year] == "2006";

OUTPUT @result
TO "/Output/ReferenceGuide/LanguageElements/Comments/exampleA.txt"
USING Outputters.Csv();

See Also

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