declare function local:getBasicTypes($productIds as xs:string*) as element(Product)* {
(: remark: @identifier = $productIds acts like a SQL @identifier in $productIds :)
collection("basicTypes/released")/Product[@identifier = $productIds]
};
let $ids := ('PH3330L', 'PH3030CL')
return
{
for $bt in local:getBasicTypes($ids)
return $bt/ProductInformation/Description
}
Now let us create an index for the @identifier and retrieve the data using this index
create index "basictype_id"
on fn:collection("basicTypes/released")/Product
by @identifier
as xs:string
declare function local:getBasicTypesByIndex($productIds as xs:string*) as element(Product)* {
for $id in $productIds return index-scan('basictype_id', $id, 'EQ')
};
let $ids := ('PH3330L', 'PH3030CL')
return
{
for $bt in local:getBasicTypesByIndex($ids)
return $bt/ProductInformation/Description
}
The result is the same for both:
<result> <Description>N-channel TrenchMOS logic level FET</Description> <Description>9657 Trench 7 (IMPULSE)</Description> </result>
Here is an example of creating an index using namespaces:
declare namespace cat = "urn:iso:std:iso:ts:29002:-10:ed-1:tech:xml-schema:catalogue";
create index "legacy_id"
on fn:collection("legacyBasicTypes")/cat:catalogue
by cat:item/cat:reference/@reference_number
as xs:string
