com.esri.arcgis.geodatabase
Interface ICursor

All Superinterfaces:

Serializable

All Known Implementing Classes:

Cursor, FeatureCursor, ICursorProxy, RelQueryCursor, TemporalCursor

public interface ICursor
extends Serializable

Provides access to members that hand out enumerated rows, field collections and allows for the updating, deleting and inserting of rows.

Remarks

Cursors are forward only; they do not support backing up and retrieving rows that have already been retrieved or making multiple passes over data. If an application needs to make multiple passes over the data, the application needs to reexecute the query that returned the cursor. If both executions of the query are made within the same edit session (or database transaction with the appropriate level of isolation), the application is guaranteed not to see any changes made to the data by other concurrently executing applications.

Note that while a cursor is created in the client's memory after a call to methods such as ITable.Search or ITable.Insert, the DBMS cursor is not created until a call to NextRow (or a similar method) is made. This is why retrieving the first row may take longer than subsequent rows, and because underlying DBMS errors might be raised on the call, error handling is recommended.

When using cursors within an edit session, they should always be scoped to edit operations. In other words, a cursor should be created after an edit operation has begun and should not be used once that edit operation has been stopped or aborted.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Method Summary

void	deleteRow() Delete the existing Row in the database corresponding to the current position of the cursor.
int	findField(String name) The index of the field with the specified name.
void	flush() Flush any outstanding buffered writes to the database.
IFields	getFields() The Fields Collection for this cursor.
Object	insertRow(IRowBuffer buffer) Insert a new Row into the database using the property values in the input buffer.
IRow	nextRow() Advance the position of the cursor by one and return the Row object at that position.
void	updateRow(IRow row) Update the existing Row in the database corresponding to the current position of the cursor.

Method Detail

findField

int findField(String name)
              throws IOException,
                     AutomationException

The index of the field with the specified name.

Remarks

If the specified field cannot be found, this method returns a value of -1.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Parameters:

name - The name (in)

Returns:

The fieldIndex

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getFields

IFields getFields()
                  throws IOException,
                         AutomationException

The Fields Collection for this cursor.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Returns:

A reference to a com.esri.arcgis.geodatabase.IFields

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

nextRow

IRow nextRow()
             throws IOException,
                    AutomationException

Advance the position of the cursor by one and return the Row object at that position.

Remarks

The NextRow method on a search or update cursor returns the next row in the result set to the application. The row object returned is allocated and hydrated by the cursor, and a reference to it is handed to the application. To retrieve all rows in a result set containing N rows, the application must make N calls to NextRow. If no rows remain in the result set, this method returns a null value.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Returns:

A reference to a com.esri.arcgis.geodatabase.IRow

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

updateRow

void updateRow(IRow row)
               throws IOException,
                      AutomationException

Update the existing Row in the database corresponding to the current position of the cursor.

Remarks

This method should only be called on update cursors.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Parameters:

row - A reference to a com.esri.arcgis.geodatabase.IRow (in)

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

deleteRow

void deleteRow()
               throws IOException,
                      AutomationException

Delete the existing Row in the database corresponding to the current position of the cursor.

Remarks

The cursor must be initialized to a row (with the NextRow method) before this method can be successfully called.

This should only be called on update cursors. To delete a row retrieved from a search cursor, call IRow.Delete on the row itself.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

insertRow

Object insertRow(IRowBuffer buffer)
                 throws IOException,
                        AutomationException

Insert a new Row into the database using the property values in the input buffer. The object ID of the new Row, if there is one, is returned.

Remarks

This method should only be called on insert cursors.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Parameters:

buffer - A reference to a com.esri.arcgis.geodatabase.IRowBuffer (in)

Returns:

A Variant

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

flush

void flush()
           throws IOException,
                  AutomationException

Flush any outstanding buffered writes to the database.

Remarks

This method should only be called on insert cursors.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.