When to use a recycling cursor in Excel?
When using a recycling cursor, the row returned by NextRow is only valid until the next call to NextRow. Any subsequent call to NextRow invalidates the previous row. Callers must release any references to the current row prior to calling NextRow. Nonrecycling cursors return a unique instance for each row returned by NextRow.
How to retrieve all rows in a cursor?
To retrieve all rows in a cursor containing N rows, the application must make N calls to NextRow. In VB6, a call to NextRow after the last row in the result set has been retrieved returns nothing. In C# .NET, this same call to NextRow returns a value of null.
What kind of object is returned by cursor?
The type of row objects returned by a cursor (the interfaces and methods supported by the row object) depends on the type of table (Object-Class, FeatureClass, or AttributedRelationship class) and its associated behavior. The row objects returned by evaluating a QueryDef are read-only.
What can a search cursor be used for?
A Search cursor can be used to retrieve rows specified by a QueryFilter and supports a NextRow method. This type of cursor can also be used to get a reference row to make updates calling the Store method. A Search cursor can be used in an edit session to fetch rows with the intent to update row values.
What does it mean when a cursor is reusing resources?
When instantiating a cursor using the Search or Update methods, the caller has the option to choose whether or not the cursor will reuse (recycle) internal resources allocated for the current row. A cursor that is reusing resources is commonly referred to as a recycling cursor.
Can a row be modified by a nonrecycling cursor?
The rows returned by a nonrecycling cursor can be modified (setting the IRow.Value property or any other custom mutator supported by the row) and stored with polymorphic behavior. The geodatabase guarantees unique instance semantics on nonrecycling row objects fetched during an edit session.
What can you do with an update cursor?
An Update cursor can be used to update and delete rows based on position and supports the NextRow, UpdateRow, and DeleteRowmethods. Similar methods exist for feature cursors (NextFeature, UpdateFeature, and DeleteFeature).