op:select

op:select(
   $plan as map:map,
   $columns, as xs:string,
   [$qualifier as xs:string?]
) as map:map

Summary

This call projects the specified columns from the current row set and / or applies a qualifier to the columns in the row set. Unlike SQL, a select call is not required in an Optic query.

Parameters
$plan	The Optic Plan. You can either use the XQuery => chaining operator or specify the variable that captures the return value from the previous operation.
$columns,	The columns to select.
$qualifier	Specifies a name for qualifying the column names in place of the combination of the schema and view names. Use cases for the qualifier include self joins. Using an empty string removes all qualification from the column names.

Example


xquery version "1.0-ml";

import module namespace op="http://marklogic.com/optic"
     at "/MarkLogic/optic.xqy";

op:from-view("main", "employees")
   => op:select(("EmployeeID", "FirstName", "LastName"))
   => op:order-by("EmployeeID")
   => op:result()