ADO Recordset Object
Voorbeelde
Hierdie voorbeeld demonstreer hoe om die GetRows-metode te gebruik.
Rekordstel Voorwerp
Die ADO Recordset-objek word gebruik om 'n stel rekords van 'n databasistabel te hou. 'n Rekordstel-objek bestaan uit rekords en kolomme (velde).
In ADO is hierdie voorwerp die belangrikste en die een wat die meeste gebruik word om data vanaf 'n databasis te manipuleer.
ProgID
set objRecordset=Server.CreateObject("ADODB.recordset")
Wanneer jy die eerste keer 'n rekordstel oopmaak, sal die huidige rekordwyser na die eerste rekord wys en die BOF- en EOF-eienskappe is Vals. As daar geen rekords is nie, is die BOF- en EOF-eiendom Waar.
Rekordstel-objekte kan twee tipes opdatering ondersteun:
- Onmiddellike opdatering - alle veranderinge word onmiddellik na die databasis geskryf sodra jy die Update-metode aanroep.
- Batch-opdatering - die verskaffer sal verskeie veranderinge in die kas kas en dit dan na die databasis stuur met die UpdateBatch-metode.
In ADO is daar 4 verskillende wysertipes gedefinieer:
- Dinamiese wyser - Laat jou toe om toevoegings, veranderinge en skrappings deur ander gebruikers te sien.
- Keyset-wyser - Soos 'n dinamiese wyser, behalwe dat jy nie byvoegings deur ander gebruikers kan sien nie, en dit verhoed toegang tot rekords wat ander gebruikers uitgevee het. Dataveranderings deur ander gebruikers sal steeds sigbaar wees.
- Statiese wyser - Verskaf 'n statiese kopie van 'n rekordstel vir jou om te gebruik om data te vind of verslae te genereer. Byvoegings, veranderinge of skrappings deur ander gebruikers sal nie sigbaar wees nie. Dit is die enigste tipe wyser wat toegelaat word wanneer jy 'n kliënt-kant Recordset voorwerp oopmaak.
- Slegs vorentoe wyser - Laat jou toe om net vorentoe deur die rekordstel te blaai. Byvoegings, veranderinge of skrappings deur ander gebruikers sal nie sigbaar wees nie.
Die wysertipe kan gestel word deur die CursorType-eienskap of deur die CursorType-parameter in die Open-metode.
Let wel: Nie alle verskaffers ondersteun alle metodes of eienskappe van die Recordset-objek nie.
Eienskappe
| Property | Description |
|---|---|
| AbsolutePage | Sets or returns a value that specifies the page number in the Recordset object |
| AbsolutePosition | Sets or returns a value that specifies the ordinal position of the current record in the Recordset object |
| ActiveCommand | Returns the Command object associated with the Recordset |
| ActiveConnection | Sets or returns a definition for a connection if the connection is closed, or the current Connection object if the connection is open |
| BOF | Returns true if the current record position is before the first record, otherwise false |
| Bookmark | Sets or returns a bookmark. The bookmark saves the position of the current record |
| CacheSize | Sets or returns the number of records that can be cached |
| CursorLocation | Sets or returns the location of the cursor service |
| CursorType | Sets or returns the cursor type of a Recordset object |
| DataMember | Sets or returns the name of the data member that will be retrieved from the object referenced by the DataSource property |
| DataSource | Specifies an object containing data to be represented as a Recordset object |
| EditMode | Returns the editing status of the current record |
| EOF | Returns true if the current record position is after the last record, otherwise false |
| Filter | Sets or returns a filter for the data in a Recordset object |
| Index | Sets or returns the name of the current index for a Recordset object |
| LockType | Sets or returns a value that specifies the type of locking when editing a record in a Recordset |
| MarshalOptions | Sets or returns a value that specifies which records are to be returned to the server |
| MaxRecords | Sets or returns the maximum number of records to return to a Recordset object from a query |
| PageCount | Returns the number of pages with data in a Recordset object |
| PageSize | Sets or returns the maximum number of records allowed on a single page of a Recordset object |
| RecordCount | Returns the number of records in a Recordset object |
| Sort | Sets or returns the field names in the Recordset to sort on |
| Source | Sets a string value or a Command object reference, or returns a String value that indicates the data source of the Recordset object |
| State | Returns a value that describes if the Recordset object is open, closed, connecting, executing or retrieving data |
| Status | Returns the status of the current record with regard to batch updates or other bulk operations |
| StayInSync | Sets or returns whether the reference to the child records will change when the parent record position changes |
Metodes
| Method | Description |
|---|---|
| AddNew | Creates a new record |
| Cancel | Cancels an execution |
| CancelBatch | Cancels a batch update |
| CancelUpdate | Cancels changes made to a record of a Recordset object |
| Clone | Creates a duplicate of an existing Recordset |
| Close | Closes a Recordset |
| CompareBookmarks | Compares two bookmarks |
| Delete | Deletes a record or a group of records |
| Find | Searches for a record in a Recordset that satisfies a specified criteria |
| GetRows | Copies multiple records from a Recordset object into a two-dimensional array |
| GetString | Returns a Recordset as a string |
| Move | Moves the record pointer in a Recordset object |
| MoveFirst | Moves the record pointer to the first record |
| MoveLast | Moves the record pointer to the last record |
| MoveNext | Moves the record pointer to the next record |
| MovePrevious | Moves the record pointer to the previous record |
| NextRecordset | Clears the current Recordset object and returns the next Recordset object by looping through a series of commands |
| Open | Opens a database element that gives you access to records in a table, the results of a query, or to a saved Recordset |
| Requery | Updates the data in a Recordset by re-executing the query that made the original Recordset |
| Resync | Refreshes the data in the current Recordset from the original database |
| Save | Saves a Recordset object to a file or a Stream object |
| Seek | Searches the index of a Recordset to find a record that matches the specified values |
| Supports | Returns a boolean value that defines whether or not a Recordset object supports a specific type of functionality |
| Update | Saves all changes made to a single record in a Recordset object |
| UpdateBatch | Saves all changes in a Recordset to the database. Used when working in batch update mode |
Gebeurtenisse
Let wel: Jy kan nie gebeure hanteer deur VBScript of JScript te gebruik nie (slegs Visual Basic, Visual C++ en Visual J++ tale kan gebeure hanteer).
| Event | Description |
|---|---|
| EndOfRecordset | Triggered when you try to move to a record after the last record |
| FetchComplete | Triggered after all records in an asynchronous operation have been fetched |
| FetchProgress | Triggered periodically in an asynchronous operation, to state how many more records that have been fetched |
| FieldChangeComplete | Triggered after the value of a Field object change |
| MoveComplete | Triggered after the current position in the Recordset has changed |
| RecordChangeComplete | Triggered after a record has changed |
| RecordsetChangeComplete | Triggered after the Recordset has changed |
| WillChangeField | Triggered before the value of a Field object change |
| WillChangeRecord | Triggered before a record change |
| WillChangeRecordset | Triggered before a Recordset change |
| WillMove | Triggered before the current position in the Recordset changes |
Versamelings
| Collection | Description |
|---|---|
| Fields | Indicates the number of Field objects in the Recordset object |
| Properties | Contains all the Property objects in the Recordset object |
Eienskappe van die Fields-versameling
| Property | Description |
|---|---|
| Count | Returns the number of items in the fields collection. Starts at zero.
Example: countfields=rs.Fields.Count |
| Item(named_item/number) | Returns a specified item in the fields collection.
Example: itemfields=rs.Fields.Item(1) |
Die Eiendomsversameling se Eienskappe
| Property | Description |
|---|---|
| Count | Returns the number of items in the properties collection. Starts at zero.
Example: countprop=rs.Properties.Count |
| Item(named_item/number) | Returns a specified item in the properties collection.
Example: itemprop = rs.Properties.Item(1) |