op:column-info( $plan as map:map ) as map:map*
This function can be used to inspect the state of a plan before execution. It returns the information about each column in the plan, including schema name, view name, column name, data type and nullability. It also returns the information about system columns.
Parameters | |
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$plan | The plan to be inspected. |
xquery version "1.0-ml"; import module namespace op="http://marklogic.com/optic" at "/MarkLogic/optic.xqy"; op:from-view("main", "employees") => op:column-info() (: results may look like below {"schema":"opticUnitTest", "view":"musician", "column":"lastName", "type":"string", "nullable":false} {"schema":"opticUnitTest", "view":"musician", "column":"firstName", "type":"string", "nullable":false} {"schema":"opticUnitTest", "view":"musician", "column":"dob", "type":"date", "nullable":false} {"schema":"opticUnitTest", "view":"musician", "column":"rowid", "type":"rowid", "nullable":false} {"schema":"opticUnitTest", "view":"musician", "column":"__docid", "type":"fraghint", "nullable":false} {"schema":"opticUnitTest", "view":"musician", "column":"__content", "type":"value", "nullable":false} :)