The LA Fox Developer Newsletter

March 2000

ADO Jumpstart (Con’t from page 1)

Filter property—The string that represents the current filter expression. This property is like the SET FILTER statement in Visual FoxPro. Unlike the Find method, multiple expressions linked with AND or OR operators are allowed. This property is only applicable to client-side recordsets.

Sort property—A comma-delimited set of fields that specifies how the rows in an ADO recordset are sorted. This property is only applicable to client-side recordsets.

State property—Specifies the state of an ADO recordset. Valid State properties are closed, open, connecting, executing, or fetching.

Status property—Specifies the editing status of the current record. Valid Status properties include unmodified, modified, new, and deleted. This property can be any one of the values contained in RecordStatusEnum.

MarshalOptions property—Specifies how records are returned (marshaled) to the server. Either all or only modified records can be returned. This property is only applicable to client-side disconnected recordsets

MaxRecords property—Specifies the total number of records to fetch from a data source.

RecordCount property—Specifies the number of records in a recordset. This property is like the Recc( ) function in Visual FoxPro.

Source property—Specifies the command or SQL statement that provides data for the recordset.

(Note: The type and location of a cursor as well as the OLE DB provider you select will affect the recordset properties that are available.)

Use the following table as a guide to help you make the right recordset type and location decision:

Only client-side recordsets can be sorted and filtered. If the CursorLocation property of ForwardOnly, KeySet, and Dynamic recordset types is set to adUseClient, making them client-side cursors, the CursorType property is automatically coerced to the Static Cursor type.

(Note: This is the behavior of the OLE DB Provider for SQL

Server. The OLE DB Provider for ODBC supports only

ForwardOnly and Static recordsets, regardless of where the

recordset resides.)

As with properties, method availability can also vary:

Table 2. Available Methods

The following list describes some of the common methods you will use in the ADO Recordset object:

MoveFirst, MovePrevious, MoveNext, MoveLast, and Move methods—Navigational methods that work as their respective names imply. The Move method accepts two arguments, the number of records to move and the position from which to begin the move. The Move method is similar to the Go statement in Visual FoxPro. MoveFirst and MoveLast work like Go Top and Go Bottom, respectively. Finally, MovePrevious and MoveNext work like Skip 1 and Skip -1, respectively.

Find method—Accepts a criterion string as an argument and searches the recordset for a match. If a match is not found, depending on the search direction, either the BOF or EOF property will evaluate to true (.T.). This method works much the same way as the Seek and Locate statements in Visual FoxPro. Unlike the Filter property and the Seek and Locate statements in Visual FoxPro, the ADO Recordset object does not allow multiple search values joined by the And or the Or operator. Using anything other than a single search value will result in an error.

Open method—Opens an existing ADO Recordset object. This method accepts several arguments and is discussed in detail later in this section.

(Con’t, page 4)

Table 1. Properties

Page 3