MarkLogic 9 Product Documentationop:on
op:on( $leftCol as item(), $rightCol as item() ) as map:map
Summary
Specifies an equijoin using one columndef each from the left and right rows. The result is used by the op:join-inner and op:join-left-outer functions.
Use op:view-col or op:col if you need to identify columns in the two views that have the same column name.
The default collation for string values in a TDE template is codepoint.
If you are having problems joining columns that use a different collation, you will need
to change the TDE template to use a matching collation, or change the appropriate range
indexes to use codepoint.
| Parameters | |
|---|---|
| $leftCol | The rows from the left view. |
| $rightCol | The row set from the right view. |
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 $totalexpenses := op:col("totalexpenses")
return $employees
=> op:join-inner($expenses, op:on(
op:view-col("employees", "EmployeeID"),
op:view-col("expenses", "EmployeeID")))
=> op:group-by(op:view-col("employees", "EmployeeID"),
("FirstName", "LastName",
op:view-col("expenses", "Category"),
op:sum($totalexpenses,
op:view-col("expenses", "Amount"))))
=> op:order-by(op:view-col("employees", "EmployeeID"))
=> op:result()