Page 286 - DCAP408_WEB_PROGRAMMING

Web Programming

Notes  ADODB.Recordset is the ProgID that should be used to create a Recordset object. Existing
applications that reference the outdated ADOR. Recordset ProgID will continue to work
without recompiling, but new development should reference ADODB.Recordset.
 There are four different cursor types defined in ADO. They are dynamic cursor, keyset
cursor, static cursor and forward-only cursor.

 Set the CursorType property prior to opening the Recordset to choose the cursor type, or
pass a CursorType argument with the Open method.
 CursorType Property indicates the type of cursor used in a Recordset object. It set or
returns a CursorTypeEnum value. The default value is adOpenForwardOnly.
 CursorLocation Property indicates the location of the cursor service. It sets or returns a
Long value that can be set to one of the CursorLocationEnum values.
 Filter Property indicates a filter for data in a Recordset. It sets or returns a Variant value,
which can contain one of the following (a) Criteria string: a string made up of one or more
individual clauses concatenated with AND or OR operators (b) Array of bookmarks: an
array of unique bookmark values that point to records in the Recordset object c) A
FilterGroupEnum value
 Fields Collection contains all the Field objects of a Recordset or Record object.
 A Recordset object has a Fields collection made up of Field objects. Each Field object
corresponds to a column in the Recordset. You can populate the Fields collection before
opening the Recordset by calling the Refresh method on the collection.

 The Fields collection has an Append method, which provisionally creates and adds a Field
object to the collection, and an Update method, which finalizes any additions or deletions.

 A Record object has two special fields that can be indexed with FieldEnum constants. One
constant access a field containing the default stream for the Record, and the other accesses
a field containing the absolute URL string for the Record.

 If you attempt to reference a nonexistent field by name, a new Field object will be appended
to the Fields collection with a Status of adFieldPendingInsert. When you call Update, ADO
will create a new field in your data source if allowed by your provider.
 When a Recordset object is passed across processes, only the rowset values are marshalled, and
the properties of the Recordset object are ignored. During unmarshalling, the rowset is unpacked
into a newly created Recordset object, which also sets its properties to the default values.

12.5 Keywords

ADODB.Recordset: It is the ProgID that should be used to create a Recordset object.

Append Method: It provisionally creates and adds a Field object to the collection.
CursorLocation Property: It indicates the location of the cursor service. It sets or returns a Long
value that can be set to one of the CursorLocationEnum values.

CursorType Property: Indicates the type of cursor used in a Recordset object.
Dynamic Cursor: Allows you to view additions, changes, and deletions by other users.
Field Object: It corresponds to a column in the Recordset.
Fields Collection: It contains all the Field objects of a Recordset or Record object.
Filter Property: It indicates a filter for data in a Recordset. It sets or returns a Variant value,
which can contain either criteria string, array of bookmarks or a FilterGroupEnum value.

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