Any better way to export double quote csv data from string object in Xquery

user_15447951 0
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It is common to export list of strings as double quote csv format in log file with Xquery for ML.

I wonder whether there is better way to do so from the list of the strings. Currently I have to use a lot of fn:concat('"', $value , '"') block to do it. It becomes difficult to read if there is a long list of values to process.

Below is the current code for a simple demo case.

xquery version "1.0-ml";

let $values := ('string 1', 'string 2', 'string N')

return fn:string-join( $values ! fn:concat('"', . , '"'), ',')

The expected output is "string 1","string 2","string N"

marklogic xquery
2 Answers

If you want to wrap every value in quotes, you could simplify slightly to something like the below.

xquery version "1.0-ml";

let $values := ('string 1', 'string 2', 'string N')

return '"' || fn:string-join($values, '","') || '"'
user_16216100

With generic XQuery 3.1, you can elegantly build up the CSV values using the arrow operator:

xquery version "3.1";

let $values := ('string 1', 'string 2', 'string N')
return
    $values
    => for-each( function($value) { '"' || $value || '"' } )
    => string-join(",")

Depending on the content of your values, you might need to apply some escaping - e.g., of commas or quotation marks.

This could easily be wrapped into a function, e.g., local:create-csv-row($values).

user_6597320
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