1. CIS 451: ASP Recordsets Dr. Ralph D. Westfall May, 2002

2. Recordset Object group of records returned by a query "cursor" initially points to 1st record can create a recordset without explicitly opening a connection Set objRS = Server.CreateObject("ADODB.Recordset")

3. Opening a Recordset objRS.Open "Product", strConnect, adOpenForwardOnly, adLockReadOnly, adCmdTable "Product" (change to database table name) strConnect = same string as for connection adOpenForwardOnly = one-way cursor adLockReadOnly = non-updateable adCmdTable = indicates that the 1st parameter (above) is a table name

4. Recordset Open Parameters objRS.Open (1st, 2nd, 3rd, 4th, 5th) can skip values e.g. (1st,,,, 5th) 3rd, 4th, 5th parameters = integer constants can hard code numeric values (,, 0, 1, 2) or use constant names with hard coded values see prodtest2.asp code can include constant values (adovbs.inc, p. 520) or from ADO type library dll p. 519

5. Recordset Parameters - 2 pulling ADO constant values into your ASP recommended (insert following tag) need to make sure that file you want is on server in specified path (OK on class server?) former method (not recommended) (open in Notepad, then see next page)

6. Recordset Parameters - 3 objRS.Open (1st, 2nd, 3rd, 4th, 5th) 1st parameter is a string, or string variable contents of 1st parameter identified by 5th: (2) adCmdTable - table name e.g. "Product" (1) adCmdText - command e.g. SQL string (8) adCmdUnknown - default plus others

7. Recordset Cursor Parameters (0) adOpenForwardOnly - not scrollable: cursor can move forward, not backward (3) adOpenStatic - scrollable, but can't see changes that occurred while viewing (2) adOpenDynamic - scrollable, and can see all changes (1) adOpenKeyset - similar to dynamic ForwardOnly = fastest, Dynamic = slowest

8. Recordset Locking Parameters (1) adLockReadOnly - no changes to source (2) adLockPessimistic - 100% locked (3) adLockOptimistic - another user can update before you (rejects your update) (4) adLockBatchOptimistic - change several records, then update (optimistic lock on each record as updated) other (non-batch) locks only update record at cursor

9. Using the Recordset Object [objectName].[property] EOF (Boolean) – objectName.EOF = true if cursor past last record end of file BOF - true if cursor moved before 1st record beginning of file Bookmark - cursor position of a specific record objectName.Bookmark moves cursor to Bookmark RecordCount - # of records in recordset

10. Using the Recordset Object - 2 move methods (objectName.[method]) cursor must be adOpenStatic or adOpenDynamic MoveFirst, MoveLast go to first or last record MovePrevious, MoveNext Move # [, Start] (positive # =forward, negative #=back) starting from Start (optional)

11. Find Records in the Recordset objectName.Find criteria[, skip, direction, start] criteria: " " put value in single quotes if has blanks, special chars compare (operator) can be >, <, =, or LIKE (with wildcards [*] in value) optional parameters skip = # of records to skip direction - defaults to adOpenForwardOnly start = bookmark

12. Find Records in Recordset - 2 example objRS.Find "Price > 4.00" when open recordset, make cursor adOpenStatic Note: search changes cursor position if no record found, cursor is at EOF (forward search), or possibly BOF with other directions can reset cursor with bookmark created before objRS.Bookmark = [variable holding bookmark]

13. Filtering Records Find moves cursor to next matching record Filter screens out all non-matching records create as a property of recordset object [objectName].Filter = [criteria] objRS.Filter = "ProdName = 'widget' " note single quotes for a string

14. Filtering Records - 2 special filters objectName.Filter = adFilterNone objRS. Filter = adFilterNone turns filter off so can access all records again objectName.Filter = adFilterPendingRecords shows records changed but not yet updated (for batch mode)

15. Review: For Each … Next can cycle through collections without knowing individual item names For Each [any name] In [collection] [code does something to each any name] Next [any name] = anything you want to call an individual item in the collection [collection] = collection name e.g. Request.QueryString, Session.Contents, etc.

16. Fields Collection contains names of all fields in recordset can access with For Each … so don't have to know field names to create output For Each fldF in objRS.Fields [code puts field names/data in html table] Next code samples: DataStore.asp, RecToTable.asp, ProdTable.asp

17. Creating Array from Recordset varArray=objRecordset.GetRows (Rows, Start, Fields) Rows = # of rows (default = here to end of file) Start = bookmark Fields = field name or # (1 = 1st column, etc.) could use variable name of an array of field names or #s as the field name

18. Access Recordset Array Data varFields=objRS.GetRows 'get rows intLastRow=UBound(varFields, 1) 'function gets row # for last row intLastCol=UBound(varFields, 2) For intRow=1 to intLastRow For intCol=1 to intLastCol 'nested loop [code to write columns for each row] [2 Nexts to close loops]

19. Exercise – 1 (code)code copy DataStore.asp to diskette and then edit change file and path to your database copy ProdTable.asp to diskette and edit change objRS.Open "Product" to name of your table (only if your table has different name) save changes, upload to your account also upload RecToTable.asp test by loading ProdTable.asp in browser

20. Exercise - 2 copy prodtest2.asp to diskette and then edit change database file to your database add fields from your database e.g. Price upload to your account and test modify it to use DataStore.asp & metadata typelib (see top of ProdTable.asp) [Dim too] replace loop with a Find change cursor parameter to adOpenStatic