ADO: ActiveX Data Objects

Determining Field Object Functionality

Earlier, the Attributes property of the Field object was introduced as a method to identify functionality available to a particular field. In the earlier example, the Attributes property was used to see whether a field contained long binary data prior to using the AppendChunk and GetChunk methods.

In addition to this attribute, the Attributes property can identify any combination of valid FieldAttributeEnum enumeration values as listed in Table 6-2.

Table 6-2. The FieldAttributeEnum Enumeration

Value	Description
adFldMayDefer	Indicates that the field value is returned only when the value is accessed rather than with the rest of the record.
adFldUpdatable	Indicates that the field value is updateable.
adFldUnknownUpdatable	Indicates that ADO cannot determine if the field value is updateable.
adFldFixed	Indicates that the field contained a fixed length of data.
adFldIsNullable	Indicates that the field value can be set to Null.
adFldKeyColumn	Indicates that the field value is a key in the data source.
adFldMayBeNull	Indicates that the Null values can be returned by this field value.
adFldLong	Indicates that the field value is a long binary value. This attribute must be set in order to use AppendChunk and GetChunk methods on a field.
adFldRowID	Indicates that the field value is a unique row identifier that cannot be set.
adFldRowVersion	Indicates that the field value is a type of time and/or date stamp used to track changes ...