MarkLogic 12 Product Documentationop:is-defined
op:is-defined( $operand as item() ) as map:map
Summary
This function tests whether the value of an expression is null in the row where the expression might be as simple as a column identified by column parameter function , such as op:col.
| Parameters | |
|---|---|
| $operand | A boolean expression, such as op:eq or op:not, that might be null. |
Example
xquery version "1.0-ml";
import module namespace op="http://marklogic.com/optic"
at "/MarkLogic/optic.xqy";
op:from-literals((
map:entry("row", 1) => map:with("sparse", 6),
map:entry("row", 2),
map:entry("row", 3) => map:with("sparse", 4)
))
=> op:where(op:is-defined(op:col('sparse')))
=> op:select(("row", "sparse"))
=> op:result()