eMbedded Visual Basic®: Windows® CE and Pocket PC Mobile Applications By
Chris Tacke, Timothy Bassett | | Table of Contents |
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| appendix A.
Control Reference |
ADOCE Control Reference
The ADOCE control is used to create and manipulate data residing in Pocket Access or SQL Server CE databases. The control is added to an eVB project via the Project/References dialog. Depending on version, it will display as "Microsoft CE ADO Control x.x", where "x.x" is the version number. The latest available version at the time of publication is 3.1. The file for the ADOCE control is adocedt30.dll or adocedt31.dll, depending on version.
Table A.17. ADOCE.Connection Properties|
| Attributes
| Long
| Implemented only with OLEDBCE providers.
| | ConnectionString
| String
| Information on where and how the connection object should open the data source. With Pocket Access, merely provide the Pocket Access file path and name. For example, ConnectionString = "\Program Files\My Application\MyPocketAccess.cdb". Note: Make sure to localize the "Program Files" directory according to the application's needs.
| | Errors
| Collection
| Collection of all ADOCE.Errors on Connection object since Connection was opened or Connection.Errors.Clear was called. See ADOCE.Error.
| | Properties
| Collection
| Provides collection of properties about the Connection. See provider documentation as to properties available. Not implemented with Pocket Access.
| | Provider
| String
| Name of the provider for the data. Pocket Access is "CEDB".
| | State
| ADOCE.ObjectStateEnum
| Provides the open or closed state of the Connection object.
| | Version
| String
| Version number of ADOCE server DLL(s).
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Table A.18. ADOCE.Connection Methods|
| BeginTrans
| None
| Begins a database transaction that supports an atomic unit of work. Not implemented with Pocket Access.
| | Close
| None
| Closes the current connection.
| | CommitTrans
| None
| Commits changes to data since last BeginTrans. Not implemented with Pocket Access.
| | Execute
| CommandText; String [RecordsAffected]; Long (ByRef) Number of records affected by data manipulation statement (Not implemented with Pocket Access) [Options]; Long Not implemented with Pocket Access. | Executes a SQL Statement statement and returns the resulting recordset.
| | Open
| [ConnectionString]; String ConnectionString to access the data store. If left blank in ADOCE, the connection will open the Windows CE Object Store. [UserId]; String User ID for access to data store. Not implemented in Windows CE Object Store or Pocket Access. Password for user ID for [Password]; String provided access to data store. Not implemented in Windows CE Object Storeor Pocket Access. | Opens a data source for access to data.
| | RollbackTrans
| None
| Discards changes made to data since BeginTrans was invoked. Not implemented in Windows CE Object Store or Pocket Access.
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Table A.19. ADOCE.Field Properties|
| ActualSize
| Integer
| Length of the field in the data store. This can be confusing for string types, because Windows CE strings are always UNICODE; therefore, the ActualSize of the field will be twice the character length.
| | Attributes
| Long
| Bit-shifted value for information about the field. It contains information such as whether the field may be updated in its current state, whether it allows NULLs, and whether it is a primary key. Refer to ADOCE documentation for these values.
| | DefinedSize
| Integer
| Length of the field as defined when it was created. This yields the capacity of the field in length.
| | Name
| String
| Name of the field.
| | NumericScale (Float).
| Byte
| Number of digits to the left of the decimal
| | Precision
| Integer
| Number of total digits available in the field.
| | Type
| ADOCE.DataTypeEnum
| Value that relates to a member of the DataTypeEnum. The actual type of the field. For example, adDate, adInt, adVarChar.
| | UnderlyingValue
| Variant
| The value of the field before it was changed (if changed). Can be useful for auditing and dirty record detection.
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Table A.20. ADOCE.Field Methods|
| AppendChunk
| Data ; Variant Information to be appended to the field.
| Appends data to a binary or text field. Implemented only with an OLEDBCE provide. Version 3.1 and higher.
| | GetChunk
| Size ; Long Number of bytes to be returned.
| Returns data from a binary or text field. Implemented only with an OLEDBCE provider. Version 3.1 and higher.
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Table A.21. ADOCE.Recordset Properties|
| AbsolutePage
| Long; Read/Write
| Position of the record within the data pages.
| | AbsolutePosition
| Long; Read/Write
| The position of the current record within the recordset.
| | ActiveConnection
| Object; ADOCE.Connection
| Returns a reference to the connection used to open the recordset. If queried directly, will return the connection. ConnectionString, as ConnectionString is the default property for the ADOCE.Connection object. | | BOF
| Boolean; Read-only
| Returns True if the AbsolutePosition is before the first record in the recordset.
| | Bookmark
| Variant; Read/Write
| If queried, returns a unique variant that if set onto the recordset will return the recordset to the same record. If set, locates the AbsolutePosition to the record where the value of Bookmark was queried from.
| | CursorType
| Long; ADOCE. CursorTypeEnum
| For Windows CE Object Store or Pocket Access, only adOpenForwardOnly and adOpenKeyset are implemented.
| | EditMode
| Long; ADOCE. EditModeEnum Read-Only
| Specifies the current state of the current record. See ADOCE.EditModeEnum.
| | EOF
| Boolean; Read-Only
| Returns True if the AbsolutePosition has been placed past the last record in the recordset.
| | Fields
| Collection; ADOCE.Fields
| Collection of all fields in the record. See ADOCE.Fields.
| | Filter
| Variant
| Returns or sets the current filtering. Only supports bookmarks and adFilterNone. Not implemented in Windows CE Object Store or Pocket Access.
| | Index
| String|Long
| Sets or returns the currently set index of the recordset. Can only be used with base table recordset (adCmdTableDirect). Can be the name of the index or the number of the index (as created). Not implemented in Windows CE Object Store or Pocket Access.
| | LockType
| Long;
| ADOCE.LockTypeEnum
| | PageCount
| Long; Read-Only
| Number of data pages in the recordset.
| | PageSize
| Long; Read/Write
| Number of records to a page.
| | Properties
| Collection; ADOCE.Properties
| Not implemented in Windows CE Object Store or Pocket Access.
| | RecordCount
| Long
| Number of records in recordset. Can return adUnknown.
| | Source
| String; Read-only after the recordset is opened. Write before the recordset is open
| The SQL string that creates the recordset or created the recordset. Set the source before Open is called. Or, can be read after therecordset is . opened.
| | State
| Long; ADOCE.ObjectStateEnum Read-Only
| Returns the open or closed state of the recordset.
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Table A.22. ADOCE.Recordset Methods|
| AddNew
| [ Fields ];Array of field to set values for. [ Values ]; Array of the values corresponding to Fields array.
| Appends a new record to the recordset. Sets values of fields if arrays provided as parameters.
| | CancelUpdate
| None
| Discards any changes made to the current record.
| | Clone
| [ LockType ]; ADOCE.LockType
| Returns a copy of the recordset.
| | Close
| None
| Closes the recordset.
| | Delete
| [ AffectRecords ]only accepts adAffectCurrent, a value of 1.
| Deletes the current record.
| | Find
| Criteria ; StringString containing the field to search upon, the comparison operator and the value. ( object. Find( "LastName = 'Smith'" [ SkipRows ]; Longoffset to start searching from current record. [ searchDirection ]; ADOCE. SearchDirectionEnum direction to search, forward, or backward. [start] ; Variant Bookmark to begin searching from. | Locates the first record matching the criteria provided.
| | GetRows
| [Rows] ; LongNumber of rows to return. [ Start ]; Long|VariantRecord number of Bookmark of where to start returning rows. [ Fields ]; ArrayFields to return values for. | Returns an array of the values from the recordset.
| | Move
| NumRecords ; LongNumber of records to offset to. [Start] ; Long|Variant Record number of Bookmark of where to start returning rows. | Move a specified offset from the current record.
| | MoveFirst
| None
| Moves to the first record of the recordset.
| | MoveLast
| None
| Moves to the last record of the recordset.
| | MoveNext
| None
| Moves to the next record of the recordset.
| | MovePrevious
| None
| Moves to the previous record of the recordset.
| | Open
| Source ; StringTable name or SQL Statement. [ ActiveConnection ]; ADOCE. ConnectionConnection to use. [ CursorType ]; ADOCE.CursorTypeCursor type for the recordset. [ LockType ]; ADOCE.LockTypeLock type for the recordset [ Options ]; LongSee provider documentation. AdCmdTableDirect is used with SQL Server CE to provide and updateable recordset. | Opens a new recordset.
| | Requery
| None
| Refreshes the recordset.
| | Supports
| CursorOptions ; ADOCE. CursorOptionEnum
| Returns Boolean as to whether the recordset supports the requested cursor option. e.g. object. Supports (adAddNew).
| | Update
| [ Fields ];Array of field to set values for. [ Values ]; Array of the values corresponding to Fields array. | Commits changes to record back to data store.
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Table A.23. ADOCE.Error Properties|
| Description
| String; Read-Only
| Friendly description of error that occurred.
| | ErrorParameters
| Collection; String
| Collection of errors from last execution attempt. Not implemented in Windows CE Object Store or Pocket Access.
| | HelpContext
| Long
| Not implemented in Windows CE at all.
| | HelpFile
| String; Read-Only
| File path to the help file for the error.
| | NativeError
| Long; Read-Only
| Native error returned from the data provider. Limited functionality with Windows CE Object Store or Pocket Access.
| | Number
| Long; Read-Only
| Error number as implemented in OLE.
| | Source
| String
| Name of the object that generated the error. Very limited implementation for Windows CE Object Store or Pocket Access.
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