MarkLogic 10 Product Documentationop:where
op:where( $plan as map:map, $condition as item() ) as map:map
Summary
This method restricts the row set to rows matched by the boolean expression. Use boolean composers such as op:and and op:or to combine multiple expressions.
A constraining document query returns only the rows from the matched source documents. If the constraining document query is a node instead of a cts:query object, the implementation calls the cts:query parser on the node. The constraining document query applies to all upstream accessors. A constraining sem:store returns only the triples from the specified store (potentially expanded by inference using a ruleset). A constraining sem:store applies to all upstream triples accessors.
| 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. |
| $condition | This can be a boolean expression, a cts:query to qualify the source documents that produced the rows set, or (where part of the row set was produced by the op:from-triples accessor) a sem:store to restrict or expand the triples that produce the row set. |
Example
xquery version "1.0-ml";
import module namespace op="http://marklogic.com/optic"
at "/MarkLogic/optic.xqy";
let $employees := op:from-view("main", "employees")
let $expenses := op:from-view("main", "expenses")
let $expenselimit := op:from-view("main", "expenselimit")
return $employees
=> op:join-inner($expenses, op:on(
op:view-col("employees", "EmployeeID"),
op:view-col("expenses", "EmployeeID")))
=> op:join-inner($expenselimit, op:on(
op:view-col("expenses", "Category"),
op:view-col("expenselimit", "Category")))
=> op:where(op:gt(op:view-col("expenses", "Amount"),
op:view-col("expenselimit", "Limit")))
=> op:select((op:view-col("employees", "EmployeeID"),
"FirstName", "LastName",
op:view-col("expenses", "Category"),
op:view-col("expenses", "Amount"),
op:view-col("expenselimit", "Limit")))
=> op:order-by(op:view-col("employees", "EmployeeID"))
=> op:result()
Example
(: Insert the template for view "docWhereExample" :)
xquery version "1.0-ml";
import module namespace tde = "http://marklogic.com/xdmp/tde"
at "/MarkLogic/tde.xqy";
let $template :=
<template xmlns="http://marklogic.com/xdmp/tde">
<context>person</context>
<collections>
<collection>docWhereExample</collection>
</collections>
<rows>
<row>
<schema-name>docWhereExample</schema-name>
<view-name>docWhereExample</view-name>
<columns>
<column>
<name>id</name>
<scalar-type>long</scalar-type>
<val>id</val>
</column>
<column>
<name>name</name>
<scalar-type>string</scalar-type>
<val>name</val>
</column>
</columns>
</row>
</rows>
</template>
return tde:template-insert("docWhereTemplate.xml", $template)
(: Insert documents :)
xquery version "1.0-ml";
let $docs := (<person><id>1</id><name>john</name><sentence>John is there</sentence></person>,
<person><id>1</id><name>joe</name><sentence>Joe was there</sentence></person>,
<person><id>2</id><name>alice</name><sentence>Alice was there</sentence></person>)
return
for $doc at $i in $docs
return xdmp:document-insert(concat("doc", $i, ".xml"),
$doc,
<options xmlns="xdmp:document-insert">
<collections>
<collection>docWhereExample</collection>
</collections>
</options>)
(: Below query returns "joe" :)
xquery version "1.0-ml";
import module namespace op="http://marklogic.com/optic"
at "/MarkLogic/optic.xqy";
op:from-view("docWhereExample", "docWhereExample")
=> op:where(op:eq(op:col("id"), 1))
=> op:where(cts:word-query("was"))
=> op:select("name")
=> op:result()