CADOField.Attributesproperty

Indicates one or more characteristics of a field.

DatabasespropertyCADOField.incdocumented

Syntax

PROPERTY Attributes () AS LONG

PROPERTY Attributes (BYVAL lAttr AS LONG)

Parameters

Name		Description
`lAttr`		Can be the sum of one or more FieldAttributeEnum values. It is normally read-only, However, for new `Field` objects that have been appended to the `Fields` collection of a `Record`, Attributes is read/write only after the Value property for the `Field` has been specified and the new `Field` has been successfully added by the data provider by calling the Update method of the `Fields` collection.
`adFldCacheDeferred`		Indicates that the provider caches field values and that subsequent reads are done from the cache.
`adFldFixed`		Indicates that the field contains fixed-length data.
`adFldIsChapter`		Indicates that the field contains a chapter value, which specifies a specific child recordset related to this parent field. Typically chapter fields are used with data shaping or filters.
`adFldIsCollection`		Indicates that the field specifies that the resource represented by the record is a collection of other resources, such as a folder, rather than a simple resource, such as a text file.
`adFldIsDefaultStream`		Indicates that the field contains the default stream for the resource represented by the record. For example, the default stream can be the HTML content of a root folder on a Web site, which is automatically served when the root URL is specified.
`adFldIsNullable`		Indicates that the field accepts null values.
`adFldIsRowURL`		Indicates that the field contains the URL that names the resource from the data store represented by the record.
`adFldLong`		Indicates that the field is a long binary field. Also indicates that you can use the AppendChunk and GetChunk methods.
`adFldMayBeNull`		Indicates that you can read null values from the field.
`adFldMayDefer`		Indicates that the field is deferred—that is, the field values are not retrieved from the data source with the whole record, but only when you explicitly access them.
`adFldNegativeScale`		Indicates that the field represents a numeric value from a column that supports negative scale values. The scale is specified by the NumericScale property.
`adFldRowID`		Indicates that the field contains a persistent row identifier that cannot be written to and has no meaningful value except to identify the row (such as a record number, unique identifier, and so forth).
`adFldRowVersion`		Indicates that the field contains some kind of time or date stamp used to track updates.
`adFldUnknownUpdatable`		Indicates that the provider cannot determine if you can write to the field.
`adFldUnspecified`		Indicates that the provider does not specify the field attributes.
`adFldUpdatable`		Indicates that you can write to the field.

Return value

One or more FieldAttributeEnum values.

Description

Indicates one or more characteristics of a field.

Remarks

When you set multiple attributes, you can sum the appropriate constants. If you set the property value to a sum including incompatible constants, an error occurs.

Example

#include once "AfxNova/CADODB.inc" USING AfxNova

' // Open the connection DIM pConnection AS CAdoConnection pConnection.Open("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=biblio.mdb")

' // Open the recordset DIM pRecordset AS CAdoRecordset DIM dvSource AS DVARIANT = "SELECT * FROM Publishers ORDER BY PubID" DIM hr AS HRESULT = pRecordset.Open(dvSource, pConnection, adOpenKeyset, adLockOptimistic, adCmdText)

' // Get a reference to the Fields collection DIM pFields AS CAdoFields = pRecordset.Fields DIM nCount AS LONG = pFields.Count IF nCount THEN PRINT PRINT "Nullable fields:" PRINT "================" PRINT FOR i AS LONG = 0 TO nCount - 1

DIM pField AS CAdoField
  pField.Attach(pFields.Item(i))
  ' // Get the attributes of the field
  DIM lAttr AS LONG = pField.Attributes
  ' // Display fields that are nullable
  IF (lAttr AND adFldIsNullable) = adFldIsNullable THEN
     PRINT "Field name: "; pField.Name
  END IF

NEXT END IF

' // === Close the recordset and the connection ' // If you don't close them, they will be closed when the application ends pRecordset.Close pConnection.Close

Reference

Include file CADOField.inc
Defined in AfxNova/CAdoFields.inc:247
Documented in Databases/ADO Classes/CAdoFields Class.md
Topic: CAdoFields Class