com.esri.arcgis.geodatabase
Interface IField

All Superinterfaces:

java.io.Serializable

All Known Subinterfaces:

IField2, IFieldEdit, IFieldEdit2

All Known Implementing Classes:

Field, IField2Proxy, IFieldEdit2Proxy, IFieldEditProxy, IFieldProxy

public interface IField

extends java.io.Serializable

Provides access to members that return information about the field.

Product Availability

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

Supported Platforms

Windows, Solaris, Linux

Description

The field object represents a column in a table. A field has many properties, the most obvious ones being its name and its datatype. The esriFieldType enumeration lists the possible datatypes.

Remarks

When you create a field of type esriFieldTypeSingle, esriFieldTypeDouble or esriFieldTypeInteger, and specify zero for precision and scale, the geodatabase will attempt to create a binary type field if the underlying database supports it. Personal geodatabases support only binary type fields. ArcGIS ignores precision and scale of binary type fields.

Depending on the precision and scale setting you select, ArcGIS may convert the field into another type. For example:

• creating a field of type esriFieldTypeDouble with a precision of 6 or less, will result in a field of type esriFieldTypeSingle
• creating a field of type esriFieldTypeSingle with a precision greater than 6, will result in a field of type esriFieldTypeSingle
• creating a field of type esriFieldTypeInteger with a precision of 10 or more, will result in a field of type esriFieldTypeDouble will be created

The length property of a field has meaning only for esriFieldTypeString fields. The length property for all other field types is not important and will be ignored if specified.

Method Summary

boolean	checkValue(java.lang.Object value) Indicates if the value is valid given the field definition.
java.lang.String	getAliasName() The alias name of the field.
java.lang.Object	getDefaultValue() The default value of the field.
IDomain	getDomain() The default domain of the field.
IGeometryDef	getGeometryDef() The geometry definition for the field if IsGeometry is TRUE.
int	getLength() The maximum length, in bytes, for values described by the field.
java.lang.String	getName() The name of the field.
int	getPrecision() The precision for field values.
int	getScale() The scale for field values.
int	getType() The type of the field.
int	getVarType() The VARTYPE of the field (e.g.
boolean	isDomainFixed() Indicates if the field's domain is fixed.
boolean	isEditable() Indicates if the field is editable.
boolean	isNullable() Indicates if the field can contain null values.
boolean	isRequired() Indicates if the field is required.

Method Detail

getName

public java.lang.String getName()
                         throws java.io.IOException,
                                AutomationException

The name of the field.

Supported Platforms

Windows, Solaris, Linux

Remarks

Depending on the geometry type, there will be fields for shape length and shape area. In a personal geodatabase, these will be named Shape_Length and Shape_Area. In an SDE geodatabase, the names of these fields will be dependant on the underlying DBMS:

DB2 - SHAPE..Length() and SHAPE..Area()

Informix - SE_Length(shape) and SE_Area(shape)

Oracle - SHAPE.LEN and SHAPE.AREA

SQL Server - SHAPE.len and SHAPE.area

The IFeatureClass::ShapeFieldName property should be used to determine the name of the length and area fields for a feature class.

Returns:

The name

Throws:

java.io.IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getAliasName

public java.lang.String getAliasName()
                              throws java.io.IOException,
                                     AutomationException

The alias name of the field.

Supported Platforms

Windows, Solaris, Linux

Remarks

This is only supported on fields from object classes and feature classes that are registered with the geodatabase; Personal, File or ArcSDE geodatabases. For fields coming from other data sources (shapefiles, coverages, etc) the AliasName will be the same string as the field name.

Returns:

The name

Throws:

java.io.IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getType

public int getType()
            throws java.io.IOException,
                   AutomationException

The type of the field.

Supported Platforms

Windows, Solaris, Linux

Remarks

The following table outlines the equivalent field data types in ArcCatalog, ArcObjects, Visual Basic and a selection of DBMSs:

ArcCatalog	esriFieldType (IField::Type)	VB Variable Type (IField::VarType)	Access	SQL Server	Oracle
Short Integer	esriFieldTypeSmallInteger	vbInteger	Number (Integer)	smallint	NUMBER
Long Integer	esriFieldTypeInteger	vbLong	Number (Long Integer)	int	NUMBER
Float	esriFieldTypeSingle	vbSingle	Number (Single)	float	NUMBER
Double	esriFieldTypeDouble	vbDouble	Number (Double)	float	NUMBER
Text	esriFieldTypeString	vbString	Text	varchar	VARCHAR2
Date	esriFieldTypeDate	vbDate	Date/Time	datetime	DATE
Object ID	esriFieldTypeOID	vbLong	AutoNumber (Long Integer)	int	NUMBER(38)
Geometry	esriFieldTypeGeometry	vbDataObject	OLE Object	int	NUMBER(38) or SDO_GEOMETRY
Blob	esriFieldTypeBlob	vbObject	OLE Object	image	NUMBER(38) or SDO_GEOMETRY
Raster	esriFieldTypeRaster	vbDataObject	Number (Long Integer)	int	NUMBER
GUID	esriFieldTypeGUID	vbString	Number (Replication ID)	uniqueidentifier	CHAR
GlobalID	esriFieldTypeGlobalID	vbString	Number (Replication ID)	uniqueidentifier	CHAR

The following table outlines the Coverage, INFO Item to Geodatabase field mapping:

Item type	Item width	Geodatabase field type (esriFieldType)
B	4	esriFieldTypeInteger
C	1-320	esriFieldTypeString
D	8	esriFieldTypeDate
F	4	esriFieldTypeSingle
F	8	esriFieldTypeDouble
I	1-4	esriFieldTypeSmallInteger
I	5-9	esriFieldTypeInteger
I	10-16	esriFieldTypeDouble
N	1-9	esriFieldTypeSingle
N	10-16	esriFieldTypeDouble

The following table outlines the Shapefile, dBASE field to Geodatabase field mapping:

Field type	Field width	Geodatabase field type (esriFieldType)
Date	-	esriFieldTypeDate
String	1-255	esriFieldTypeString
Boolean	-	esriFieldTypeString
Number	1-16 (decimals = 0)	esriFieldTypeInteger
Number	1-16 (decimals > 0)	esriFieldTypeDouble

Returns:

A com.esri.arcgis.geodatabase.esriFieldType constant

Throws:

java.io.IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getDomain

public IDomain getDomain()
                  throws java.io.IOException,
                         AutomationException

The default domain of the field.

Supported Platforms

Windows, Solaris, Linux

Returns:

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

Throws:

java.io.IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

See Also:

IDomain

getDefaultValue

public java.lang.Object getDefaultValue()
                                 throws java.io.IOException,
                                        AutomationException

The default value of the field.

Supported Platforms

Windows, Solaris, Linux

Returns:

A Variant

Throws:

java.io.IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getLength

public int getLength()
              throws java.io.IOException,
                     AutomationException

The maximum length, in bytes, for values described by the field.

Supported Platforms

Windows, Solaris, Linux

Returns:

The length

Throws:

java.io.IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getPrecision

public int getPrecision()
                 throws java.io.IOException,
                        AutomationException

The precision for field values.

Supported Platforms

Windows, Solaris, Linux

Remarks

Precision is the number of digits in a number. For example, the number 56.78 has a precision of 4. Precision is only valid for fields that are numeric. Precision is always returned as 0 from personal or File geodatabase fields.

Returns:

The length

Throws:

java.io.IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getScale

public int getScale()
             throws java.io.IOException,
                    AutomationException

The scale for field values.

Supported Platforms

Windows, Solaris, Linux

Remarks

Scale is the number of digits to the right of the decimal point in a number. For example, the number 56.78 has a scale of 2. Scale applies only to fields that are double. Scale is always returned as 0 from personal or File geodatabase fields.

Returns:

The length

Throws:

java.io.IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

isNullable

public boolean isNullable()
                   throws java.io.IOException,
                          AutomationException

Indicates if the field can contain null values.

Returns:

The isNullable

Throws:

java.io.IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getGeometryDef

public IGeometryDef getGeometryDef()
                            throws java.io.IOException,
                                   AutomationException

The geometry definition for the field if IsGeometry is TRUE.

Supported Platforms

Windows, Solaris, Linux

Returns:

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

Throws:

java.io.IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

See Also:

IGeometryDef

getVarType

public int getVarType()
               throws java.io.IOException,
                      AutomationException

The VARTYPE of the field (e.g. VT_I4).

Supported Platforms

Windows, Solaris, Linux

Description

Returns an Integer indicating the subtype of a variable.

Remarks

The following is a list of the Vartype constants

Constant	Value	Description
vbEmpty vbNull vbInteger vbLong vbSingle vbDouble vbCurrency vbDate vbString vbObject vbError vbBoolean vbVariant vbDataObject vbDecimal vbByte vbArray	0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 17 8192	Uninitialized (default) Contains no valid data Integer subtype Long subtype Single subtype Double subtype Currency subtype Date subtype String subtype Object Error subtype Boolean subtype Variant (used only for arrays of variants) Data access object Decimal subtype Byte subtype Array

Returns:

The varType

Throws:

java.io.IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

isDomainFixed

public boolean isDomainFixed()
                      throws java.io.IOException,
                             AutomationException

Indicates if the field's domain is fixed.

Supported Platforms

Windows, Solaris, Linux

Returns:

The isFixed

Throws:

java.io.IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

See Also:

IDomain

isRequired

public boolean isRequired()
                   throws java.io.IOException,
                          AutomationException

Indicates if the field is required.

Supported Platforms

Windows, Solaris, Linux

Description

All tables and feature classes have a set of required fields that are necessary to record the state of any particular object in the table or feature class. These required fields are automatically created when you create a new feature class or table, and cannot be deleted. Required fields may also have required properties such as its domain property. You cannot modify the required property of a required field.

For example, in a simple feature class, OID and Shape are required fields. They do have properties such as their alias and geometry type that you can modify, but these fields cannot be deleted.

Returns:

The isRequired

Throws:

java.io.IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

isEditable

public boolean isEditable()
                   throws java.io.IOException,
                          AutomationException

Indicates if the field is editable.

Supported Platforms

Windows, Solaris, Linux

Remarks

It is best to loop through the fields of a feature and skip the fields that are not editable, rather than allowing users to attempt to edit fields that cannot be edited.

Returns:

The isEditable

Throws:

java.io.IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

checkValue

public boolean checkValue(java.lang.Object value)
                   throws java.io.IOException,
                          AutomationException

Indicates if the value is valid given the field definition.

Supported Platforms

Windows, Solaris, Linux

Description

CheckValue tests whether the specified value is valid for the current field, based upon the field type. For example, CheckValue will verify if the supplied value corresponds to field type of Small Integer or if the value corresponds to a string value.

The value is not checked against any existing domain.

Parameters:

value - A Variant (in)

Returns:

The isValidValue

Throws:

java.io.IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.