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If * The resulting value will be a map with a {{Code|formatrecords}} is set to and an optional {{Code|mapnames}}, key.* Records are organized as a sequence of arrays. A single array contains the CSV data entries of a single record.* The column names will be converted available if {{Code|header}} option is set to an XQuery map:{{Code|true}}.
* All records are enumerated with positive integersThe CSV map can e.* By default, all entries of a records are represented in a sequence.* If the {{Code|header}} option is set to {{Code|true}}, a map is created, which contains all field names and its valuesg.be accessed as follows:
'''A little advice''': in * <code>$csv?records[5]</code> returns all entries of the Database Creation dialog 5th record (row)* <code>$csv?records(2)</code> returns all entries of the GUI2nd field (column)* <code>$csv?names?*</code> returns the names of all fields (if available)* Return enumerated strings for all records:<pre class="brush:xquery">for $record at $pos in $csv?recordsreturn $pos || ". " || string-join($record?*, if you select CSV Parsing and switch to the ''Parsing', ' tab)</pre> The resulting representation consumes less memory than XML-based formats, you and values can see the effects of some of the be directly accessed without conversion options. Thus, it is recommendable for very large inputs and for efficient ad-hoc processing.
{{Mark|Updated with Version 8.6}}: improved Excel compatibility
let $text := file:read-text('some-data.csv')
no edit summary
=Conventions=
All functions and errors in this module are assigned to the <code><nowiki>http://basex.org/modules/csv</nowiki></code> namespace, which is statically bound to the {{Code|csv}} prefix.<br/>All errors are assigned to the <code><nowiki>http://basex.org/errors</nowiki></code> namespace, which is statically bound to the {{Code|bxerr}} prefix.
==Conversion==
===XML: Direct, Attributes===
If the {{Code|direct}} or {{Code|attributes}} format is chosen, a CSV string is converted to XML as follows:
* The resulting XML document has a {{Code|<csv>}} root element.
* If {{Code|format}} is set to {{Code|attributes}}, field names will be stored in name attributes.
'''A little advice''': in the Database Creation dialog of the GUI, if you select CSV Parsing and switch to the ''Parsing'' tab, you can see the effects of some of the conversion options. ===MapXQuery=== With the {{Code|xquery}} format, CSV records are converted to a sequence of arrays:
==Options==
In the following table, all available options are listed. The Excel column indicates what are the preferred options for data that is to be imported, or has been exported from Excel.
|- valign="top"
| {{Code|separator}}
| Defines the character which separates the entries values of a single record in a single line.
| {{Code|comma}}, {{Code|semicolon}}, {{Code|colon}}, {{Code|tab}}, {{Code|space}} or a ''single character''
| {{Code|comma}}
|- valign="top"
| {{Code|format}}
| Specifies the format of the XML data. The format is only relevant if the {{Code|header}} option is activated:<br/>
* With {{Code|direct}} conversion, field names are represented as element names
* With {{Code|attributes}} conversion, field names are stored in {{Code|name}} attributes
* With {{Code|mapxquery}} conversion, the input is converted to an XQuery map| {{Code|direct}}, {{Code|attributes}}, {{Code|mapxquery}}
| {{Code|direct}}
|
==csv:parse==
{{Mark|Updated with Version 9.1:}} support for empty sequence.
{| width='100%'
|-
| width='120' | '''Signatures'''
|{{Func|csv:parse|$input string as xs:string?|document-node(elementitem(csv))?}}<br/>{{Func|csv:parse|$input string as xs:string?, $options as map(xs:string, item()*)?|item()?}}
|-
| '''Summary'''
|Converts the CSV data specified by {{Code|$inputstring}} to an XML document or a mapXQuery value. The {{Code|$options}} argument can be used to control the way the input is converted.
|-
| '''Errors'''
|{{Error|BXCS0001parse|#Errors}} the input cannot be parsed.
|}
|-
| width='120' | '''Signatures'''
|{{Func|csv:serialize|$input as nodeitem()?|xs:string}}<br/>{{Func|csv:serialize|$input as nodeitem()?, $options as map(xs:string, item()*)?|xs:string}}
|-
| '''Summary'''
|Serializes the node specified by {{Code|$input}} as CSV data, and returns using the result as specified {{Code|xs:string$options}}, and returns the result as string. Items Values can also be serialized as JSON if CSV with the standard [[Serialization|Serialization Parameter]] feature of XQuery:* The parameter {{Code|method}} is needs to be set to {{Code|csv}}.<br/>The , and* the options presented in this article need to be assigned to the {{Code|$optionscsv}} argument can be used to control the way the input is serializedparameter.
|-
| '''Errors'''
|{{Error|BXCS0002serialize|#Errors}} the input cannot be serialized.
|}
'''Query:'''
<pre class="brush:xquery">
let $options := map { 'lax': false() }
let $xml input := csvfile:parseread-text($text, $options'some-data.csv')let $output := $input => csv :parse($options) = > csv:serialize($xml, $options)return $text input eq $csvoutput
</pre>
'''Example 3:''' Converts CSV data to an XQuery map item and serializes its contentsreturns distinct column values:
'''Query:'''
<pre class="brush:xquery">
let $text := "``[Name;,City" || outJack,ChicagoJack,WashingtonJohn,New York]``let $options := map { 'format':nl() || "John;Newton" || out'xquery', 'header':nltrue() || "Jack;Oldtown"}let $options csv := <csv:parse($text, $options>)return ( <csv 'Distinct values:separator value=';'/>, <csv let $records :format value=$csv('maprecords'/>) < for $name at $pos in $csv:header value=('yesnames'/>)?* </csvlet $values :options>= $records($pos) return csv( '* ' || $name || ':parse' || string-join(distinct-values($textvalues), ', $options') ))
</pre>
'''Result:'''
<pre class="brush:xmlxquery">{ 1Distinct values: { "City"* Name: "Newton"Jack, "Name": "John" }, 2: { "* City": "Oldtown"Chicago, Washington, "Name": "Jack" }}New York
</pre>
|Description
|-
|{{Code|BXCS0001parse}}
| The input cannot be parsed.
|-
|{{Code|BXCS0002serialize}}
| The node cannot be serialized.
|}
=Changelog=
; Version 9.1
* Updated: [[#csv:parse|csv:parse]] can be called with empty sequence.
;Version 9.0
* Added: {{Code|xquery}} option
* Removed: {{Code|map}} option
* Updated: error codes updated; errors now use the module namespace
;Version 8.6
